WO2004059457A1

WO2004059457A1 - Compact data entry systems

Info

Publication number: WO2004059457A1
Application number: PCT/NL2003/000899
Authority: WO
Inventors: Evgeny Pavlovich Kuzmin
Original assignee: Rl Technologies B.V.
Priority date: 2002-12-24
Filing date: 2003-12-17
Publication date: 2004-07-15
Also published as: AU2002358352A8; WO2004059456A8; AU2002358352A1; WO2004059456A1; AU2003295261A1; WO2004059457A9

Abstract

A compact data entry system comprises functional zones (2) uniformly divided over an input surface and switches (6) organized in functional groups. Each functional group of switches (6) is associated with a functional zone (2). A functional zone (2) is activated when at least one of its associated functional groups is activated. The system further comprises a processing device (3). The processing device (3) detects the activation of said switches (6) and further detects the activation of a functional group of switches (6) after the member switches (6) of said functional group are activated. When activation of a functional group of switches (6) is detected, the processing device (3) activates a function corresponding to the activated functional group.

Description

Compact data entry system

The present invention relates to a data entry system, in particular to a compact data entry system for portable or handheld electronic devices. Further, the present invention relates to the use of said data entry system.

The functionality of electronic hand-held devices, such as hand-held computers, cellular and smart telephones, electronic dictionaries and translators, personal information managers, labelers and smart watches, continues to increase, and electronic components become smaller and smaller. Most of such devices require alphanumeric input. Several solutions for data entry for such devices exist like compact keyboards, virtual keyboards, handwriting recognition, voice recognition, etc. Among them, a most convenient solution is a keyboard, because it is fast, very intuitive and reliable.

A problem of a keyboard for hand-held devices is the size of its keys in relation to the fingertips to be used for data entry. As human fingertips are relatively constant in size, they conventionally limit a key to a smallest possible size and therefore the size of a conventional keyboard is limited to a minimum.

Some known keyboards have to be used in combination with a pointing device, since the keys on the keyboard are made too small in size to be activated with a finger. A pen-like pointing device has to be used to point at or push each key. This method demands accurate coordination of the pointing device, which can be very difficult e.g. when travelling.

Another known technique to minimize the size of a keyboard uses combinations of keys to address more functions with fewer keys, possibly in combination with smaller keys.

US Patents 4,400,593 and 4,994,992 disclose devices in which legend symbols corresponding to groups of keys are placed at intersections of key boundaries. By pressing at the intersection, multiple keys are pressed and activated. The combination of these keys corresponds to an input function different from the function of the individual keys. Although the keys are still separately operable, the number of functions per unit area of the keyboard surface is increased.

A combination of key size reduction and key grouping is disclosed in US Patent 5,612,690. The publication shows a keypad with a two-leveled structure, one level for individual keys, and another level for groups of keys. The keys have dimensions about half the dimensions of a key of a usual computer keyboard. Each key has a function associated with it, and combinations of four keys, adjacent to each other, have other functions associated with them. The centers of the keys are elevated for ergonomic use, making it possible to activate only one key by pressing the center of a single key or to activate four adjacent keys by pressing at the lowered intersection of the boundaries of four keys situated between the elevated centers.

Legend symbols are situated in the center of each key and at the intersection of the boundaries of four adjacent keys. As a result, the legend symbols at the intersections are divided over the four corners of the four adjacent keys. Further, the legend symbols have different dimensions depending on their position, i.e. in the center of a key or at the intersection of four keys.

Input functions are divided over the input surface non- uniformly. Some functions are activated by pressing one key and other functions by pressing four keys.

Problems of the prior art are the complex structure of the keypad, the non-uniformity of division of input functions, and the variation in legend symbol sizes which make use impractical and non-intuitive.

Another problem is the readability of the key legends . As the keys are already small, the legends are small and therefore difficult to read, and a division of the legend symbol in two or more parts makes reading of the legend symbol practically impossible. It is an object of the present invention to provide a compact data entry system that is small, user-friendly and intuitive, especially for, but not limited to, hand-held devices.

It is another object of the present invention to provide a compact data entry system that is suitable for input using fingertips, in particular having all functions accessible by a single finger stroke.

It is a further object of the present invention to provide a compact data entry system with a large number of functions per unit area.

It is a still further object of the present invention to provide a compact data entry system having readable legend symbols .

It is an even further object of the present invention to provide a compact data entry system having input functions, which are uniformly divided over the input surface.

At least one of the above-mentioned objects is achieved by a data entry system according to the present invention comprising: an input surface, divided into a plurality of functional zones; a plurality of switches, organized in functional groups of switches, each functional group being associated with one of the functional zones, at least one functional zone having an associated functional group of switches comprising at least two switches; and a processing device for detecting activation of one or more of said switches and for activating a function after activation of a functional group of switches is detected, wherein that the plurality of switches is arranged such that each switch of a functional group associated with a functional zone is positioned within a predetermined activation contact area associated with said functional zone, a center of the activation contact area being positioned at a center of said functional zone, and wherein the processing device is adapted for detecting activation of a functional group of switches comprising any number of switches.

The data entry system according to the present invention combines key size reduction and key grouping effectively. By defining functional zones that are not uniquely associated with one switch, it is possible to have a compact data entry system that is small enough to fit on a hand-held device, but is also intuitive and simple.

It is noted that in a keyboard according to the present invention, the switch arrangement with respect to the functional zone arrangement is substantially different from common keyboards. In common keyboards the switches are associated with basic functions, and extra functionality is added by associating functions with switch combinations, the switch arrangement thus being dependent on a basic functional zone arrangement.

A keyboard according to the present invention uses a different approach. One or more switch combinations are assigned to and associated with a functional zone. The switch arrangement is decoupled from a basic functional zone arrangement. There are no basic functions and additional functions distinguishable. In an embodiment however wherein one switch is positioned in a functional zone, said switch may be individually associated with said functional zone.

The switch arrangement is dependent on a predetermined activation contact area. An activation contact area represents a contact area being covered on the input surface when an activation object activates a functional zone. An activation object is preferably a fingertip, but may be any other kind of object such as an above-mentioned pointing device. When the activation object touches or points at the input surface, the activation object covers a part of the input surface. This area being covered is the activation contact area.

The dimensions of the activation contact area depend on the activation object. Therefore, when designing a keyboard according to present invention, it should be clear what kind of activation object is expected to be used. Preferably, and according to an object of the present invention, this is a human fingertip. Note that for a keyboard of a portable device, the activation contact area is generally larger than the associated functional zone, possibly covering a part of another functional zone. However, the activation contact area may as well be smaller than the associated functional zone.

The switches are arranged such that the activation object activates all switches of a functional group of switches associated with the functional zone being activated. This implies that the fingertip, i.e. the activation contact area, may cover not only the functional zone being activated, but also other functional zones. The functional groups associated with the adjacent functional zones, however, are not activated, because each of them contains at least one switch positioned outside the activation contact area.

Since the switches comprised in a functional group associated with a functional zone lie within an activation contact area associated with said functional zone, these switches lie near or at the boundary of said functional zone. Although the activation contact area may be larger than the functional zone, the activation contact area is positioned with respect to the functional zone such that the associated switches need to lie at least near or possibly at the boundaries of said functional zone.

All the switches of a functional group associated with the functional zone being activated lie within the associated activation contact area and are activated. Any other functional zone has at least one associated switch lying outside said activation contact area. This switch may lie near the boundary of the activation contact area, or further away.

The processing device detects activation of a functional group of switches. A number of switches in a functional group may depend on the functional zone being activated. Further, a functional zone may have a number of associated functional groups comprising different numbers of switches. Therefore, the processing device is adapted to detect activation of a functional group comprising any number of switches. The input surface may be a flat or a convex plane or may be any other arbitrary shaped surface; it may be hard or flexible or may combine hard and flexible parts. Essentially, it is divided in functional zones. Activating a functional zone by activating the switches of an associated functional group of switches activates an input function of the data entry system.

The input surface may show legend symbols to the user. A legend symbol represents the input function associated with a functional zone. Preferably, the legend symbols are situated within the functional zones enabling the user to activate a function by pointing to, pressing at or touching the legend symbol. However, legend symbols might be placed nearby, but outside a functional zone. Moreover legend symbols do not need to be present. For example, when the data entry system is used for activation by a visually handicapped person, legend symbols are not needed.

Legend symbols could be embedded, printed or reproduced at the input surface permanently or be placed at interchangeable surfaces like additional overlays or underlays in case of a transparent input surface. The legend symbols may also be dynamically rendered at the input surface using electronic displays or the like. Preferably all symbols have the same size, but one or more groups of symbols may have a different color and/or size for better visual perception. Further, if a functional zone has multiple associated input functions, in combination with another functional zone such as a ^ΛSHIFT'-key for example, said functional zone may have more than one legend symbol .

Preferably, the input surface gives also tactile feedback to the user about the place of the functional zones. With tactile feedback, a user may feel the location of a functional zone. If the input surface is three-dimensionally curved at the location of each functional zone, the user may feel whether or not his fingertip is positioned correctly to activate a single functional zone. Such tactile feedback may be formed by molded key caps in an elastic material, or by grooves, bumps, dots or painted lines defining the boundaries or other parts of the functional zones. Additionally, there may be audible feedback, for example a sound when activating a functional zone or when an error occurs, or visual feedback, for example back lighting of the legend symbols, or both.

The switches are organized in functional groups. Each functional group may have any number of member switches, depending on the shape and size of the functional zones. A functional zone on the input surface is activated, when the member switches of a functional group associated with said functional zone are activated.

Each switch is member of one or more functional groups. Further, in combination with other switches, a switch may be associated with multiple functional zones, and each functional zone may have more than one associated functional group of switches. For example, if a functional zone has four switches at its boundaries, but any combination of three of said four switches is unique for said functional zone, five functional groups may be associated with said functional zone: four functional groups of three switches and one functional group of four switches. Additionally, two diagonally positioned switches may form a functional group, thus giving two more possible functional groups . Said functional zone may thus have even seven associated functional groups. Further, in combination with other switches, said four switches might be associated with any other functional zone situated near said functional zone.

The switches may be any kind of switch. They may be electronic, electromechanical, mechanical or optical switches, for example. Any kind of activation of the switches such as touching, pressing or pointing is usable. Preferably, the switches are touch sensitive or force sensitive sensors, such as used in usual computer keyboards. Users are familiar with this kind of key activation. Further, a switch has dimensions smaller than the dimensions of a functional zone, possibly almost equal to the dimensions of a functional zone.

The data entry system comprises a processing device that detects the activation of the switches. Upon detection of the activation of the member switches of a functional group, the processing device activates a function corresponding to the activated functional group.

Advantageously the switches associated with a functional zone are situated at or near the boundary of said functional zone. When a switch is situated at the boundary, the center of said switch is situated at the boundary of at least one functional zone. The boundary may also be the boundary of two or more functional zones. In that case, a switch situated at the boundary is positioned between the centers of said two or more functional zones and within the two corresponding activation contact areas. Thus, said switch may be a member switch of one or more functional groups associated with each of said two or more functional zones .

Further, a switch may be situated just outside or partly inside a functional zone or in an area between two or more functional zones. Thus, said switch is situated near the boundary of at least one functional zone. If a switch is situated at the boundary, just outside a functional zone or between two or more functional zones, the dimensions of said switch are preferably small relative to the dimensions of the functional zones, in particular having a maximum cap size as seen in any direction of approximately 1-3 mm.

As mentioned above, in an embodiment, a switch may be situated in a functional zone. In such an embodiment, at least one other functional zone does not have a switch situated inside the functional zone. The functional zone, in which no switch is situated, is activated by activation of at least two switches situated in other functional zones. Said switches need to lie within the activation contact area corresponding to said functional zone in order to be activated when an attempt is made to activate said functional zone by a fingertip, for example.

A functional zone is activated, when the associated switches, which form a functional group of switches, are activated. The processing device detects the activation of said switches. The processing device detects also the activation of said functional group of switches. As soon as the activation of the functional group of switches is detected, the processing device activates a function corresponding to the activated functional zone.

Advantageously the activation of a functional group is independent of any time constraint. A user action should trigger the processing device to detect the activation of a functional group of switches. Such a user action may be activating a switch or deactivating a previously activated switch. Thus, the processing device should be adapted for detecting activation of a functional group of switches, when, after at least one switch is activated, at least one activated switch is deactivated.

When a switch is activated, the processing device checks whether or not the activated switch forms a functional group in combination with other activated switches, if there are any other activated switches, or else it checks whether or not the switch forms a functional group individually. If a group of activated switches forms a functional group associated with a functional zone, the processing device checks whether or not another functional group associated with another functional zone may be activated by activation of another switch. If such other functional group may be activated, the processing device waits for a user action. If a functional group is detected, which functional group determines a functional zone, the processing device activates the corresponding function. In any other case, the processing device activates an error function, e.g. an audible signal.

If one or more switches are activated and these switches form a functional group associated with a functional zone, but is a part of another functional group associated with another functional zone, the processing device waits for a user action. If the user deactivates at that point at least one of the activated switches, the processing device checks whether or not the group of switches that were activated just before at least one of the activated switches was deactivated, form a functional group associated with a functional zone. If they do, the processing device activates the corresponding function or else it activates an error function.

After the processing device has activated a function corresponding to a functional zone, or an error function, it waits until all activated switches are deactivated. As soon as all switches are deactivated, it waits until a first switch is again activated and the detection of possible functional groups starts over again.

In a case wherein a functional zone has two associated functional groups of switches, one group being a subgroup of the second functional group, the associated input function is activated when activation of the first functional group is detected. All subsequent switch activations and deactivations may be ignored, until all switches are deactivated, providing a high level of reliability.

In another case processing is continued after detection of activation of a first functional group and activating the corresponding first input function associated with said first functional group. After activation of the first input function, the processing device keeps on checking for switch activations and deactivations . When another activated functional group is detected, the processing device activates the corresponding input function. Such processing allows continuous detection of activated functional groups by finger dragging over the input surface.

The above-described detection methods are user-friendly, because a user action activates detection of a functional group such as activation or deactivation of a switch. There are no time constraints. However, if a switch is activated for a predetermined time the processing device may check whether or not a functional group is activated to assist users who like the data entry system to respond to activation instead of deactivation of a switch.

Advantageously, when the switches are situated inside a functional zone, each switch forms a functional group individually and is also a member of one or more other functional groups, associated with one or more other functional zones. Thus, a function may be associated with an individual switch and another function may be associated with a functional group of switches comprising said switch and one or more other switches.

Preferably, the division of the input surface in functional zones is uniform and regular, i.e. the functional zones have the same size and shape and are positioned in a systematic way. A uniform division of the input surface enables uniform legend symbols. Uniformity of size and regularity of placement of functional zones and legend symbols improve the readability of the legend symbols and therefore the user-friendliness of the data entry system. Above that, uniformity and regularity make a selection and activation of the functional zones intuitive. For example, the functional zones may be round, oval, square, rectangular, triangular or hexagonal. However, the subdivision may be any mosaic subdivision, possibly containing a number of different shapes. Different shapes may be employed to visually distinguish or emphasize one or more groups of functional zones and their associated input functions.

It is preferred that the switch arrangement is uniform and regular. A uniform and regular switch arrangement is more cost- effectively produced, as no complex structure needs to be designed and constructed. Further, if the switches are visible or at least distinguishable to a user, a regular and uniform switch arrangement will not disorientate and distract the user.

Advantageously, the input surface may be made of a single, continuous volume of elastic material or of a combination of a hard frame and elastic material, which may hide the switches. This is advantageous, because the switches may be arranged such that the arrangement differs from the arrangement of the functional zones. Such an arrangement could disorientate the users. If the switches are covered by the input surface, users do not notice the positions of the switches and therefore they will not be disorientated.

As the material is elastic, activation of a functional zone deforms the surface locally, activating the switches associated with said functional zone. After release of the functional zone, the elastic material returns to its former shape.

In an embodiment the keyboard comprises keys with the look of common keys which are activated by switches connected to or positioned under the edge of the keys. Pressing the key will activate the switches situated under the edges. However, the switches may be activated individually and not only in combination with said key. Pressing in an area between keys (no key present) activates a number of the switches positioned under the edges of the adjacent keys. Said switches form a functional group. Thus, the area between said adjacent keys forms a number of functional zones associated with a number of input functions. A key may have elevated portions at the positions of the switches, thereby showing to the user where the switches are positioned.

In such an embodiment users experience a usual keyboard with a number of common keys. The keys may for example be associated with numbers and the areas between them with alphanumeric symbols and functions, providing a telephone-like arrangement. Despite the elevations the user experiences a usual telephone keypad, but also experi-ences a switch arrangement according to the present invention. The user gets thus used to the switch arrangement. When a keyboard without the common looking keys but with visible switches at the boundary of functional zones, is later presented to the user, the user will not be disorientated by the switch arrangement with respect to the functional zone arrangement, but will recognize the switch arrangement. Using the aforementioned keys with elevated portions, the user adapts easily to the switch arrangement according to the present invention.

For user adaptation it is also preferable that the function arrangement i.e. keyboard layout approaches the layout of usual keyboards, such as a common "QWERTY"-keyboard. Such a layout was designed for full size keyboards. On most portable devices, a replica of such a layout does not fit. Therefore, the functions, which are positioned in one row or column of a common keyboard layout, may not be situated in one row or column anymore but in another coherent arrangement. A row may for example be replaced by a V-shaped arrangement of two rows, thereby providing a row to be activated by a fingertip of a left hand and one row to be activated by a fingertip of a right hand. Other possible arrangements comprise different linear zigzag and circular arc patterns .

The shape and arrangement of the functional zones may be adapted to the shape of a fingertip or a thumb and its orientation, defining the activation contact area depending on the application of the keyboard. As an activation contact area of a fingertip is not a circle, but an oval, the shape of the functional zones may be oval. Also, like a circle being scaled down to an oval, other shapes may be scaled down in one dimension. For example, if it is expected that users will use their thumbs to activate functional zones, their shape and size may be adapted to the shape and size of a thumb.

For example, a user usually uses his fingers to support a handheld device, and his thumb to activate keys. In such a case, a symmetry axis of the oval contact area of the thumb is about 40° rotated with respect to a horizontal (or vertical) axis. Note that the direction of the rotation depends on the thumb in question: the left-hand thumb (-40°) or the right-hand thumb (+40°) . A two-thumb keyboard may therefore be divided in two parts, one for a left-hand thumb and one part for a right-hand thumb, each part being adapted in size and orientation to the corresponding thumb.

In addition, in contact with a convex shaped object, in particular a cylindrical object, e.g. a pen, pencil or pointing device, the activation contact area of a fingertip is smaller than the activation contact area of a fingertip and a flat surface. Therefore, on a convex shaped object, the pitch between switches along the perimeter of the convex surface of the object may be further reduced.

In electronic hand-held devices, the processing device comprises preferably an electronic circuit. This circuit may comprise logical circuitry suitable for detection of the activation of a functional group, when at least one switch is activated. Still, the detection may be done in any other way.

Hand-held and portable devices are often subjected to rough handling and bumping. Moving parts are sensitive to such handling. Therefore, in an embodiment, the data entry system comprises switches each comprising a conductive activation pad electrically connected to an input of the processing device, the activation pads being spaced apart, wherein a functional zone may be activated by electrically connecting the activation pads of at least two switches. Said embodiment does not comprise any moving parts and detects activation of at least two switches simultaneously and is therefore more reliable. It is to be noted that the described embodiment is only usable for keyboards wherein all functional zones are activated by activation of a combination of switches .

To reduce the complexity of the underlying circuitry and the number of inputs of the processing device, a plurality of activation pads may be connected to one input of the processing device. If each functional zone has a functional group of switches connected with a unique combination of inputs of the processing device, the activated functional zone is unambiguously determinable . The processing device detects which inputs are electrically connected and derives from the combination of connected inputs, which functional zone was activated.

In an embodiment, a flat or curved plane is provided with conductive pads as switches, and a human fingertip simultaneously touching two or more activation areas electrically connects said two or more activation areas.

In a further embodiment, a layer of electrically conducting material is positioned over said activation pads and applying a pressure on said electrically conducting layer may electrically connect two or more activation pads. Such an embodiment does not depend on the electrical conductivity of a fingertip providing more reliable keyboard processing.

Another practical embodiment comprises a. a first layer having a first surface having conductive paths and insulative paths between the conductive paths; b. a second layer being flexible and having a first surface having conductive paths and insulative paths between the conductive paths, the second layer having a second surface having activation areas positioned thereon opposite to the conductive paths on said first surface of the second layer; said first surface of the first layer being positioned opposite to the first surface of the second layer, the surfaces being spaced apart such that applying a pressure on an activation area on the second surface of the second layer electrically connects a unique combination of a conductive path of the second layer and a conductive path of the first layer, the conductive paths of the first and of the second layer being connected to inputs of the processing device.

Preferably, the first layer and the second layer are identical layers. An embodiment comprising two identical layers is cost-effectively produced. One large sheet is produced and two parts are cut therefrom. The two parts are positioned opposite to each other, the first surfaces facing each other. The second surface of any one of the layers is used as an input surface.

Advantageously, a third layer of an electrically conducting material is positioned between the first and the second layer, so applying a pressure on an activation area of the input surface will electrically connect said third layer with a conductive path on the first layer and with a conductive path on the second layer. Such a third layer speeds the detection by the processing device.

Without the third layer, the processing device needs to check every combination of conductive paths of the first layer and conductive paths of the second layer. If the first layer comprises N conductive paths, and the second layer comprises M conductive paths, the processing device needs to verify N * M combinations for an electrical connection.

With the conductive third layer connected to an input of the processing device, the processing device needs to check for at least two electrical connections between the third layer and at least two conductive paths. This means that every combination of third layer and any conductive path needs to be checked for an electrical connection. This equals a total of N + M checks, instead of N * M. In case N and M equal 8, the total number of checks is reduced by a factor of four. Thus, the processing device can check four times faster for connected conductive paths .

Further, the present invention relates to the use of a compact data entry system in a hand-held device, in particular in a hand-held computer, a cellular or smart phone, an electronic dictionary or translator, a personal information manager, a calculator, a labeler or a smart watch. However, it is noted that the present invention may be embodied in any data entry system wherein a high functional density is preferred. Other systems than hand-held portable devices include avionics systems, control systems, security systems, and the like.

Even further, the present invention relates to the use of a data entry system in a convex, in particular cylindrical object, in particular a pointing device, a pencil or a pen.

In a further aspect, the present invention relates to a method for detecting activation of at least two switches comprised in a data entry system, each switch comprising an activation pad electrically connected to an input of a processing device, the method comprising detecting an electrical connection' between at least two inputs of the processing device.

In a further method, the data entry system further comprises a conductive material, which may make an electrical connection between the activation pads of at least two switches, and which is electrically connected to an input of the processing device, the further method comprising a step of detecting an electrical connection between the conductive material and at least two activation pads.

Hereinafter the present invention will be illustrated in more detail with reference to the annexed drawings showing non- limiting exemplary embodiments . Fig. la shows a perspective view of an embodiment of the present invention as a compact telephone keypad; Fig. lb shows a partly schematic top view of the embodiment according to Fig. la; Fig. 2 shows a diagram illustrating the detection method of activated functional groups . Figs. 3a and 3b show a perspective view of embodiments of the input surface. Fig. 4 illustrates the size of an adult human fingertip according to ISO-standard 9241-4. Figs. 5a-5e illustrate square, triangular and hexagonal placement of switches for minimum-sized functional zones; Figs. 6a-6e illustrate possible layouts of functional zones and switches; Figs. 7a -7d show embodiments according to Figs, la and lb with a minimum number of switches; Figs. 8a-8g illustrate embodiments according to the present invention with switches situated within functional zones; Fig. 9 illustrates a minimum size and spacing of switches within functional zones in relation to the size of an adult human fingertip according to the ISO-standard

9241-4; Figs. lOa-lOm show possible layouts for embodiments of the present invention with switches situated at corners of functional zones; Fig. 11a shows a perspective view of an embodiment according to the present invention with switches situated within functional zones; Fig. lib shows a possible layout for the embodiment according to Fig. 10a; Fig. lie shows another possible layout of an embodiment according to the present invention with switches situated within functional zones; Figs, lld-llf show possible embodiments of a telephone keypad Fig. 12a illustrates a layout using hexagonal functional zones and having switches situated within functional zones; Fig. 12b shows a pad according to the present invention for movement of a cursor in any direction; Fig. 13a shows another preferred embodiment of the present invention having bar-shaped switches between functional zones; Fig. 13b shows an embodiment with a minimum number of bar- shaped switches between functional zones; Fig. 14a shows a schematical perspective view of one layer with a surface having conductive paths and insulating paths between the conductive paths according to an embodiment of the present invention; Fig. 14b schematically illustrates an embodiment comprising two of the layers illustrated in Fig. 14a; Fig. 14c schematically illustrates a pattern formed by the conductive paths of a first and a second layer in the embodiment illustrated in Fig. 14b; Fig. 14d shows a side view of an embodiment according to Fig.

14b, wherein portions of the outer surface are elevated; Fig. 15 schematically illustrates an activation detection method for detecting activation of an activation area of an embodiment illustrated in Figs. 14b and 14c; Fig. 16 shows a perspective side view of an embodiment according to Fig. 14b, wherein a conductive third layer is positioned between the first and second layer; Figs. 17a - 17b schematically illustrate an embodiment having a flat surface with activation pads according to the present invention; Figs. 18a - 18b schematically illustrate an embodiment having a convex surface with activation pads according to the present invention; Figs. 19a-19d show cross sectional and top views of embodiments using switches at key edges; and Figs. 20a-20b show possible telephone keyboard layouts.

In the drawings, identical reference numerals indicate similar components or components with a similar function.

Figs, la and lb show a perspective view of a numeric (telephone) keypad 1 having functional zones 2. Each functional zone 2 has a legend symbol 4 associated with it. At each corner of the functional zones 2 a switch 6 is located. Further, the contours of an adult human finger 8 are shown. The finger 8 is activating functional zone 2a provided with legend symbol ^Λ8' . Switches 6a, 6b, 6c and 6d are associated with functional zone 2a. For clarity, the switches 6a-6d are shown as black dots. However, their physical embodiment may be the same as the other switches 6.

Fig. lb schematically shows a processing device 3 connected to the numeric keypad 1 through one or more lines 3a. The processing device 3 detects the activation of the switches 6 and the activation of functional groups of switches 6. Further, the processing device 3 activates a function through one or more lines 3b when the processing device 3 detects the activation of a functional group of switches 6. All data entry systems according to the present invention, parts of which are shown in the drawings, are provided with a processing device. However, the processing device is not explicitly shown in the other drawings.

The switches 6 are combined in functional groups . A functional group is associated with a functional zone 2. In Figs, la and lb, for example, switches 6a-6d situated at the corners of the functional zone 2a may form a functional group associated with functional zone 2a. The members of said functional group, i.e. switches 6a-6d, may each also be member of other functional groups. Switches 6b and 6c situated at the corners of functional zone 2b may together with switches 6e and 6f form a functional group associated with the functional zone 2b.

Further, to activate functional zone 2a, it is not necessary that all four member switches 6a-6d of the functional group be activated. A combination of the switches 6a, 6b and 6c is also a unique combination for functional zone 2a. Thus, in general, activation of a functional zone 2 may be detected upon activation of any unique combination of switches 6. In case of the embodiment of Figs, la and lb, even two switches 6 may identify a functional zone 2: activation of two diagonally situated switches 6a and 6c (or 6b and 6d) is enough to identify the activation of functional zone 2a.

A functional zone 2 has more than one associated switch 6. Thus, activation of said functional zone 2 needs activation of more than one switch 6. As activation of multiple switches 6 will almost never be simultaneous, the processing device has to wait until all switches 6 of a functional group are activated. In case activation of a functional group is unique for a functional zone 2, i.e. additional activation of other switches 6 cannot lead to activation of a functional group associated with another functional zone 2, there is no need for a time delay. The processing device may activate a corresponding function immediately.

On the other hand, there may be more or less than four switches 6 in a functional group associated with a functional zone 2. Any unique combination of switches 6 may be associated with a functional zone 2. In the embodiment of Figs, la and lb, a usual number of switches 6 to form a functional group is four.

In Figs, la and lb, the finger 8 is activating the functional zone 2a. As the finger 8 is larger than the functional zone 2a, it touches not only the functional zone 2a but also a part of at least a number of adjacent functional zones 2 with legend symbols ', ^Λ5', ^λ6', ^Λ7', 9' _. ^λ*', 0' and ^λ#' . Also, the switches 6a-6d situated at the boundaries of the functional zone 2a and the boundaries of adjacent functional zones 2 are touched. When activating functional zone 2a, the switches 6a-6d being members of the functional group associated with functional zone 2a are activated by the finger 8. Activation of the functional group, and detection thereof, results in activation of a corresponding function, which in the present embodiment may be inputting the digit 8' into a terminal while dialing a telephone number .

In the embodiment of Figs, la and lb, the functional zones 2 may have a height and width of about one third of the size of an adult human finger tip, i.e. about 5 to 6 mm. Thus, the keypad 1 has a width of about 15 to 18 mm and a height of about 20 to 24 mm. Realizing that a key on a common computer keyboard has a width and height of about 19 mm, the keypad 1 has nine functional zones 2 in an area having the size of a usual key.

Fig. 2 is a diagram demonstrating a detection method in case a functional group is also a subgroup of another functional group, i.e. if said functional group is activated, activation of another switch may activate another functional group of switches. The horizontal axis represents time T. On the vertical axis an active state SI and non-active state SO of three switches SW1, SW2 and SW3 are placed. The dashed lines represent five time points tl, t2, t3, t4 and t5. At tl switches SW1 and SW3 are activated; switch SW2 is activated at t2. The switches SW1, SW2 and SW3 are deactivated at t5, t4 and t3, respectively.

At tl the processing device detects the activation of two switches : SW1 and SW3. At that point it checks whether or not switches SWl and SW3 form a functional group that is uniquely associated with a functional zone, which means that activation of another switch will not result in the activation of another functional group associated with another functional zone. If the switches SWl and SW3 do form a uniquely associated functional group, the processing device activates the corresponding function. If the switches SWl and SW3 do not form a uniquely associated functional group, the processing device waits until another switch is activated or at least one of the switches SWl and SW3 is deactivated before the processing device again checks whether or not a functional group is activated.

At t2 another switch SW2 is activated. Again the processing device checks for a uniquely associated functional group. If the three activated switches SWl, SW2 and SW3 are not uniquely associated with a functional group, the processing device waits again.

At t3 the switch SW3 is deactivated and returns to its non- active state SO. Now, the processing device checks whether or not the three switches SWl, SW2 and SW3 form a functional group at all. If they form a functional group, the processing device activates the corresponding function and waits until all switches are deactivated. If they do not form a functional group, the processing device assumes that the activation of switch SW3 was unintended and ignores its activation. The processing device checks whether or not SWl and SW2 form a uniquely associated functional group and may activate the corresponding function or may wait for other events .

As soon as switch SW2 is deactivated at t4, the processing device checks whether or not SWl and SW2 form a functional group and may activate the corresponding function or may wait for other events. If still no functional group is detected at t4, the processing device checks at t5 whether or not switch SWl forms a functional group individually and may activate the corresponding function or it waits until another switch is activated.

Figs. 3a and 3b show embodiments of input surfaces with tactile feedback. The input surface in Fig. 3a has curved functional zones 2 like keys. The center of a functional zone 2 is elevated with respect to its boundaries. The switches 6 are situated at the lowered corners of the functional zones 2. In Fig. 3b, the center of a functional zone 2 is lowered with respect to its boundaries and the switches 6. In both embodiments, the surface may be hard like common computer keyboard keys, but the surface may also be flexible, for example made of an elastic material.

The functional zones 2 in Figs. 3a and 3b provide tactile feedback to the user. The user feels whether or not his fingertip is correctly placed on a functional zone 2. This tactile feedback minimizes the chance of unintentional activation of adjacent functional zones 2. The input surfaces could be made of flexible material and hide underlying switches 6. The input surfaces of Figs . 3a and 3b are particularly well suited to be handled by visually handicapped persons.

Fig. 4 illustrates the size of an adult human finger 8. ISO- standard 9241-4 defines a contact area 12. This contact area 12 is the area that is ergonomically needed by an adult human finger for activation of a key on a keyboard. The contact area 12 is a circle with a radius 14 of 9.5 mm (3/8 inch). Therefore, a square key 16 should have sides with a length 18 of about 19 mm (3/4 inch) . As above-mentioned, the size of keys on a common computer keyboard is about 19 mm.

In Figs. 5a, 5b, 5c and 5d, the square key 16 and the contact area 12 according to ISO-standard 9241-4, are shown, having dimensions as described above. A functional zone 2a lies in the center of the contact area 12. Switches 6 are situated at the boundaries of said functional zone 2a. Depending on the shape of the functional zone 2a, there are three (Fig. 5b: triangular placement and Fig. 5d: hexagonal placement), four (Fig. 5a: square placement) or six (Fig. 5c: hexagonal placement) switches 6a-6f at the corners of the functional zone 2a. Three, four or six of the switches 6a-6f form a functional group associated with the functional zone 2a. The switches 6a-6f lie also inside the contact area 12. No other switches 6 lie inside the contact area 12. Any functional group of switches associated with any other functional zone 2 contains at least one switch 6g positioned outside the contact area 12. The distance between the center 20 of the functional zone 2a and the switch 6g is indicated by reference numeral 22. The distance 22 should at least be a half of the corresponding dimension of the contact area 12. It is noted that the member switches 6a-6f may also be member switches of functional groups associated with other functional zones.

When activating the functional zone 2a, nearby located functional zones 2 should not be activated. The switches 6a-6f form the functional group associated with functional zone 2a. When these switches 6a-6f are activated, the detection device detects the activation of the functional zone 2a. If no other switches 6 lie inside the contact area 12, they will not be activated, when the functional zone 2a is activated. To prevent unintentional activation, any functional group of switches not associated with functional zone 2a should comprise a switch positioned outside the contact area 12. Thus, the size of contact area 12 determines the minimum distance 22 between the center 20 of the functional zone 2a and a switch 6g distinguishing a not- associated functional group. The distance 22 should be about 9.5 mm according to ISO-standard. In practice, the size of the contact area 12 of a human finger and a flat surface is about 13 - 17 mm, and therefore the distance 22 may even be 6.5 - 8.5 mm. Figs. 5a, 5b, 5c and 5d illustrate a method to determine the minimal distance between adjacent switches 6 for square (Fig. 5a) , triangular (Fig. 5b) and hexagonal (Fig. 5c and 5d) placement of the switches 6.

Fig. 5d shows another possible embodiment having hexagonal zones. A functional zone 2a has only three switches 6a - 6c at its boundary. In this case non-associated switches 6d - 6f are located within the corresponding contact area 12, but their activation may be ignored. However, in combination with above- mentioned three associated switches 6a - 6c, they may be member of an associated functional group. Further, any combination of two switches of said three switches 6a - 6c may form an associated functional group as their combination is unique to the functional zone 2a. The embodiment of Fig. 5d has about twice more functional zones per unit area than the embodiment of Fig. 5c.

Fig. 5e illustrates a case wherein the contact area 12 is not a circle, but a rotated oval corresponding to a thumb contact area. The oval contact area 12 with center 20 covers triangular functional zone 2a having an associated functional group of switches 6a - 6c. All the not associated switches 6d - 6h lie outside the contact area 12. Due to the decreased size of the contact area compared to a circular contact area the number of functional zones per unit area is increased. The same approach may be employed using functional zones being square or hexagonal or having any other shape. The contact area 12 may also be adjusted, for example based on fingertip shapes and positions.

Figs. 6a, 6b, 6c and 6d show possible layouts for functional zones 2, using a triangular placement of switches 6. All four embodiments have the same triangular layout of switches 6. However, the layout of the functional zones 2 differs. In the layout of Fig. 6a, each functional zone 2 has three associated switches 6, although activation of a functional zone 2a may be detected by activation of at least two of three associated switches 6a, 6b and 6c.

In Fig. 6b, the number of functional zones 2 is more than twice the number of functional zones 2 in Fig. 6a, although the number and layout of the switches 6 is identical. However, as a result of the increased number of functional zones 2, an activation of a functional zone 2a may only be detected by the activation of at least three associated switches 6a, 6b and 6c.

A layout with triangular functional zones 2 illustrated in Fig. 6c has more functional zones 2 per unit area than the layouts in Fig. 6a, but a functional zone 2a may only be identified by at least three associated switches 6a, 6b and 6c.

The layout illustrated in Fig. 6d is essentially the same as the one illustrated in Fig. 6c, although the functional zones 2 are hexagonal. This layout has at least two embodiments corresponding to Figs. 5c and 5d. In the first case, it has the same number of functional zones 2 per unit area as the layout of Fig. 6a, and each functional zone 2a may be identified by at least two of three switches 6a - 6c. In the second case the layout has twice more functional zones per unit area, but a functional zone 2a may only be only identified by at least three switches 6a - 6c.

Fig. 6e illustrates an embodiment, which has a more complex division of the input surface in functional zones. Triangular and square zones 2a, 2b are combined. The triangular zones 2a may be activated if three corresponding corner switches 6a-6c are activated and square functional zones if four 6b-6e, or two diagonally positioned switches 6b, 6d, or 6c, 6e, are activated. In Fig. 7a, a layout with switches 6 and fake switches 24 around square functional zones 2 is shown. The layout approaches the one shown in Fig. la and lb, only some switches 6 are replaced by fake switches 24. In this embodiment, a functional zone 2a has only two associated switches 6a and 6b and two fake switches 24a and 24b, although the fake switches 24 may also be omitted.

Replacement or omission of the switches 6 is possible, because in the layout having switches 6 at each corner of a functional zone 2, activation of a functional zone 2 may be detected by activation of fewer than four associated switches 6.

In the embodiment illustrated in Fig. 7b, the number of switches 6 is also minimized. Switches 6 are located in the center of the keypad 1 and fake switches 24 replace the switches 6 at the edges of the keypad 1. As a result, the number of associated switches 6 is different for functional zones 2a, 2b and 2c. A corner functional zone 2b has one associated switch 6a, a side functional zone 2c has two associated switches 6a and 6b, and a center functional zone 2a has four associated switches 6a, 6b, 6c and 6d.

If different functional zones 2 have different numbers of associated switches 6, the processing device has to be adapted to detect the activation of the functional group, which the user intended to activate. A short, predetermined time delay may be used or preferably, the detection method demonstrated in Fig. 2 may be used. This method is less sensitive to erroneous input, because it only responds to user actions.

The layout in Fig. 7c is similar to the layout in Fig. 7b, but it is rotated over 45 degrees and some switches at the boundaries are omitted. This layout has three or four switches at the boundaries of the functional zones forming the associated functional groups. All functional groups uniquely determine the functional zones and their corresponding functions .

In the embodiment shown in Fig. 7d even more switches have been omitted compared to the layout of Fig. 7c. Here, like in Fig. 7a each functional zone has only two associated switches. Figs. 8a-8b illustrate embodiments wherein a switch 6 is situated within a functional zone 2. There are also functional zones 2 without a switch 6. A functional zone 2a with a switch 6a may be activated by activation of this switch 6a only. However, the functional zone 2a in Fig. 8a may also be activated by a functional group of five switches 6a, 6b, 6d, 6e and 6f. A functional zone 2b may be activated by switches 6a, 6b, 6c and 6d situated in adjacent functional zones 2.

Figs. 8c, 8d and 8e show possible layouts when hexagonal or triangular functional zones 2 are used and switches 6 are situated in the functional zones 2. In Fig. 8c, the functional zone 2b is activated by activation of two adjacent switches 6a and 6b. In Fig. 8d, three adjacent switches 6a, 6b and 6c are needed for activation of functional zone 2b. In Fig. 8e, the number of adjacent switches 6 needed for activation differs. The functional zone 2b is activated by activation of the switches 6a, 6b and 6c; the functional zone 2c is activated by activation of the switches βc and 6d.

In Figs. 8a - 8e, the switches 6 are shown almost as large as the functional zones 2. However, these switches 6 may also have small contact surfaces as shown in Fig. 8f. Fig. 8f shows a layout identical to the layout of Fig. 8b, but having smaller switches 6. An activation contact area 12 corresponding to a functional zone 2a is illustrated. An object having an activation contact area 12 activates functional zone 2a. Switch 6a should be activated and other switches 6 should not be activated. The distance between the not-associated switches 6b and 6c should be larger than the dimension of the activation contact area 12. As seen in Fig. 8f, with these small switches 6, the dimensions of the functional zones 2 may be almost a quarter of the dimensions of the activation contact area 12, while with large switches 6, as seen in Fig. 8b, the dimensions of the functional zones 2 may be only a third of the dimensions of the corresponding activation contact area.

Fig. 8g illustrates an embodiment having functional zones 2 of different shapes (triangles, squares and hexagons) and switches 6 situated in the hexagonal functional zones. A hexagonal zone 2a is activated by activation of one switch 6a located in said zone, a square zone 2b by activation of two adjacent switches 6a and 6b, and a triangular zone 2c is activated by activation of three adjacent switches 6a, 6b and 6c.

Fig. 9 illustrates the necessary spacing between adjacent functional zones 2a, 2c and 2e with switches and functional zones 2b and 2d without switches. According to ISO-standard 9241-4, the adult human fingertip 8 needs at least a width 38 of 19 mm (3/4 inch) to ergonomically push a key or button, but in practice the size of a human fingertip 8 is about 13 - 17 mm.

As seen in Figs. 8a and 8b, in a configuration with switches 6 situated within functional zones 2, the spacing between and the size of switches 6 should be equal in order to have uniform functional zones 2. In Fig. 9, when activating the functional zone 2c, the switches 2a and 2e should not be touched. The distance 38 between switches 2a and 2e should therefore be at least 19 mm. This allows the dimensions 36 of a key cap to be about one quarter of the size of an adult human fingertip 8, i.e. about 5 mm, as indicated in Fig. 9. As described in relation to Fig. 8f, the switches 2a, 2c and 2e may also be pin switches with small contact surfaces. Figs. lOa-lOe show keypads 1 according to the present invention. Switches 6 are situated at the corners of the functional zones 2. Fake switches 24 are situated at the edges of the keypad 1. The fake switches 24 at the edges may also be omitted.

Fig. 10a shows a keypad 1 with the layout of a usual telephone keypad. Fig. 10b shows a common keyboard layout ("QWERTY") . As modern hand-held computers have about the same width as this embodiment, this keypad 1 is very suitable for hand-held computers .

The keyboard in the Fig 10c is very similar to previous one as it presents a "QWERTY" keyboard layout, but it uses hexagonal functional zones and may therefore have a higher functional density. For smaller devices like phones, credit card-sized PDA such width is already not suitable, because standard phone or credit card width is about 4-5 cm. Therefore special efforts are necessary to reduce the width of the keyboard preserving ergonomics and familiarity of regular QWERTY keyboards .

To reduce the width of a keyboard regular linear keyboard rows are placed in a zigzag pattern. In one embodiment the centers of any three sequential functional zones form a triangle. The angles of these triangles could be 30 (Figs. lOe and lOg) , 45 (Fig lOd) , or 60 degrees (Fig lOh) , but any other value is also possible. The zigzag pattern could be even more complex as shown in Fig. lOf, wherein a horizontal and a 30 degrees displacement is used, or more simple like a V row pattern illustrated in Fig. 101. The embodiment of Fig. 101 is very suitable for two-thumb tapping.

The common idea for all these embodiments is to use extra vertical space in order to get a reduction of horizontal dimension. Above-mentioned embodiments provide "QWERTY"-keyboards with a width in the range from 33 to 48 mm.

This idea is also applicable to regular micro-keyboards in order to reduce their width. The functional zones are then formed by regular buttons . A regular keyboard layout corresponding to the one illustrated in Fig. lOh is shown in Fig. 10J .

In Fig. 10k, the data entry system is divided over four parts 71, 72, 73 and 74. These parts are shifted slightly relative to each other. The embodiment is suitable for blind, four-finger typing. Each of the four fingers on one hand is placed on one of the keyboard parts 71, 72, 73 and 74. With only a small finger movement, each finger may activate one of nine functional zones 2 and there is no need for any movement of the hand.

Fig. 101 shows an embodiment of a full Japanese Kana data entry system suitable for hand-held devices .

Fig. 10m shows another layout of a data entry system. The letters are arranged according to their frequency of use to minimize finger movement. Above that, the letters are arranged such that letters of frequently used letter combinations are situated next to each other, allowing a user to drag his finger over the input surface and not having to lift his finger from the input surface.

Enabling dragging of a finger over the input surface requires minimal changes in the processing algorithm. The processing device should register activation of a functional group and instead of waiting for deactivation of all switches of said activated functional group, immediately start detecting whether a next activated functional group is activated. This approach could be combined with most of the above mentioned and illustrated embodiments. Continuous switch processing provides acceleration of input speed. Embodiments with small switches not comprising any movable parts are especially well suited for smooth finger dragging and corresponding processing.

Fig. 11a shows a keypad 1 of a common cellular telephone. The keypad 1 comprises twelve switches 6: ten switches 6 for each digit and two switches 6 for *' and ^Λ#' . The switches 6 are positioned with some space between them.

According to the present invention, the space between the switches 6 may be used as additional functional zones 2. Fig. lib shows a layout for a keypad 1 according to the present invention with switches 6 situated inside functional zones 2. This embodiment comprises fifteen switches 6, offering enough functions to comprise ten numerals, twenty-six letters and a number of additional functions and punctuation marks . Compared to the telephone keypad 1 in Fig. 11a, only three switches 6 are added.

Fig. lie illustrates a keypad 1 like the one shown in Fig. lib. Only, four switches 6 are added compared to Fig. 11a, positioned at the right side.

Many cellular telephones have a keypad 1 like the keypad 1 shown in Fig. 11a. An alphanumeric keypad 1 may be implemented on cellular phones without many hardware changes. Addition of three or four switches 6 and additional software make the numeric keypad 1 also suitable for alphanumeric input. Some other possible embodiments of a phone keypad utilizing a triangular zone layout, preserving familiar placement of numeric areas and adding "QWERTY" or "ABC" alphanumeric keyboard functionality are shown in Figs, lid - llf. The embodiment in Fig. lid is well suited for two-thumb tapping.

Fig. 12a illustrates an embodiment using hexagonal functional zones 2 arranged in a circle. Functional zones 2 with switches 6 are indicated by fattened hexagons. The other functional zones 2 lack a switch 6.

Fig. 12b illustrates a pad 40 for cursor movement. The pad 40 having four switches 6 may direct a cursor in eight different directions 42.

Most software has a graphical user-interface nowadays. This interface uses a cursor or pointer, which is commonly controlled by a mouse. For hand-held computers, an external pointing device, such as a mouse, is not practical. With the use of a pad 40, a cursor or pointer may be directed in eight directions 42.

In the center of the circle of functional zones 2 shown in Fig. 12a, the pad 40 may be provided for movement of a cursor.

Fig. 13a illustrates an embodiment of the present invention having bar-shaped switches 6 between functional zones 2. A functional zone 2a has four associated switches 6a, 6b, 6c and 6d. Activation of at least two of the associated switches 6a-6d activates the functional zone 2a.

Fig. 13b illustrates an embodiment like the embodiment in Fig. 12a, but only ten switches 6 are used. A functional zone 2a on the side of the keypad has two associated switches 6a and 6d and a functional zone 2b in the middle has four associated switches 6a, 6b, 6c and 6d.

Fig. 14A - 14C illustrate an embodiment of a keypad constructed of two identical layers. Fig. 14A shows one such layer 100. The layer 100 comprises a basic flexible sheet 102. This flexible sheet may be any electrically insulating material. The sheet material 102 should be flexible: it should elastically, and preferably locally, deform when a preferably small pressure is exerted on it. On one side of the sheet 102 there are alternating rows of electrically insulating 104 and conducting 106 paths. These paths 104, 106 should also be flexible. This is especially important for the conductive path 106 as it should stay conductive and not crack due to any deformation. The insulating paths 104 are elevated with respect to the conducting paths 106.

Fig. 14B shows a side view of a keypad comprising two of the layers shown in Fig. 14A. One flexible sheet 102A is illustrated with its side having the conductive and insulating paths 106A, 104A thereon, upwards, and a second layer comprising a flexible sheet 102B with its side having insulating paths 104B downwards. The conductive paths 106B of the second layer are not visible in Fig. 14B. The second layer has been rotated over 90° with respect to the first layer. Thus, the elevated insulating paths 104A and 104B are positioned on top of each other at intersections 110 of a rectangular grid 108 (Fig. 14C) . Between the intersections 110 conductive paths 106A and 106B are positioned opposite to each other, but also spaced apart.

Applying pressure on a sheet 102A or 102B at an activation area 112 between the insulating paths 104 will deform the sheet 102 and will result in an electrical connection between a conductive path 106A and a conductive path 106B. Detecting an electrical connection between two conductive paths 106A and 106B determines unambiguously which activation area 112 has been activated.

An embodiment of a keypad as illustrated in Figs. 14A - 14C may cost-effectively be produced. The basic layer comprising a flexible sheet, conductive and insulating paths is easily produced and cheap. It may be produced in large sheets. From the large sheets, small sheets may be cut and placed on top of each other.

Fig. 15 illustrates a detection method for detecting activation of an activation area 112 of the embodiment illustrated in Figs. 14A - 14C. One of the two sheets 102 and the conductive paths 106A and 106B of the two layers are shown schematically. The conductive paths 106 are connected to an activation detection device 114.

The detection device 114 may apply a voltage to a first of the conductive paths 106A of the first layer. With the voltage applied to one the conductive paths 106A, the detection device 114 checks whether there is a voltage on one or more of the conductive paths 106B of the second layer. Thus, the detection device 114 may determine an electrical connection between the first conductive path 106A of the first layer and one of the conductive paths 106B of the second layer.

Next, the detection device 114 applies a voltage to a second conductive path 106A of the first layer and checks for a voltage on one or more of the conductive paths 106B of the second layer. Thus, the detection device 114 checks one after another each conductive path 106A for an electrical connection with a conductive path 106B. Next, the detection device 114 starts with the first conductive path 106A again. Using this method, the detection device 114 has to perform M * N checks to detect activation of any activation area 112, wherein M is the number of conductive paths 106A and N is the number of conductive paths 106B.

The outer surface of one or both flexible sheets 102A and 102B may comprise elevated areas at the position of the activation areas 112. Such an elevation functions to give tactile feedback to a user over the position of the activation areas 112, and the elevation localizes applied pressure on the center of the activation area 112.

Localization of applied pressure by elevations on the sheets 102A and 102B can advantageously be employed for activation of a number of activation areas 112. If a fingertip is aimed between two or four elevated activation areas 112, i.e. at one insulating path 104 or an intersection 110 of two insulating paths 104, the pressure is divided over the adjacent activation areas 112, especially when the area between the activation areas 112 is relatively small compared to the fingertip. Fig. 16 illustrates a further embodiment of a keypad with two identical layers. Two of the layers shown in Fig. 14A comprising sheet 102A and insulating paths 104A; and a sheet 102B and insulating and conductive paths 104B, 106B are positioned on top of each other. A third layer is positioned between the two layers. The third layer is a flexible conductive sheet 116.

Detection of activation of any activation area 112 may be performed by applying a voltage to the conductive sheet 116. Thus, the detection device 114 need only to check for a voltage on one or more conductive paths 106A and one or more conductive paths 106B. This requires M + N checks instead of M * N like in the embodiment of Figs. 14B - 14C. In case of an embodiment with 64 activation areas 112 having 8 conductive paths 106A and 8 conductive paths 106B, The detection of activation of any activation area 112 may be performed four times faster (16 (8+8) checks instead of 64 (8 * 8) checks) .

Figs. 17A - 17B schematically illustrate another embodiment of a keypad wherein activation of a functional group by registering simultaneous activation of more than one switch is employed. A basic plate or sheet 120, such as a printed circuit board (PCB), comprises on one side conductive pads 122. The conductive pads 122 are connected to an activation detection device (not shown) via a first or a second set of conductive paths 124 or 126. Basically, the first and second conductive paths 124 and 126 are the same. However, the first conductive paths 124 are parallel to each other, as are the second conductive paths 126, but the first set of conductive paths 124 are rotated with respect to the second set of conductive paths 126.

In the practical embodiment shown in Fig. 17A, the first set of conductive paths 124 is positioned on one side of the PCB 120 and the second set 126 is positioned on the other side of the PCB 120. The conductive pads 122 are all positioned on one side of the PCB 120. A connection from a conductive pad 122 to a conductive path 126 of the second set is made through the PCB 120. The arrangement of pads 122 and conductive paths 124 and 126 as shown in Fig. 17B is such that any electrical connection of two adjacent (horizontally, vertically, or diagonally adjacent) conductive pads results in a unique electrical connection between two conductive paths 124 and 126. This may be a connection between a conductive path of the first 124 and of the second 126 set, but may also be a combination of two conductive paths from the first 124 or second 126 set of conductive paths. Hence, making an electrical connection between two adjacent conductive pads 122 may unambiguously be determined by the activation detection device.

A human fingertip may make the electrical connection between two or more adjacent conductive pads.- Such an embodiment of a keypad does not comprise any moving parts, which makes it very reliable. Detection may be performed as described in relation to Fig. 15. Further, the keypad may be cost-effectively produced because of the common, commercially available parts and simple layout of the PCB.

The electrical connection may as well be made by a conductive foil positioned over and spaced apart from the PCB 120. Applying a pressure on the foil will electrically connect adjacent conductive pads 122. This foil may also be used to speed the detection process analogous to the method described in relation to Fig. 16.

The keypad embodiment of Fig. 17A and 17B is only applicable to keypads wherein switch combination is employed (at least two switches per functional group of switches) , whereas the embodiment described in relation to Figs. 14 - 16 could be used for keypads wherein a single switch or activation area is a functional zone with a function.

An embodiment of a keypad without moving parts may advantageously be employed in very small objects or non-flat surfaces. A cylindrical object, for example a pointing device, may comprise such a keypad. Fig. 18A shows a schematical perspective view of a cylindrical object 130 such as a pointing device or a pen. A number of conductive pads 132 are positioned at the outside of the object 130. Inside or at least under the outer surface of the object 130, the conductive pads 132 are connected to an activation detection device.

Fig. 18B shows a top view of the cylindrical object 130 with conductive pads 132. For clarity, the conductive pads 132 are illustrated as being elevated with respect to the outer surface of the cylindrical object 130. However, the pads 132 do not need to be elevated. Further, a fingertip 135 is shown.

Due to the cylindrical shape of the object 130, the contact area 136 of the fingertip 134 touching the object 130 is smaller than touching a flat surface. Therefore, the pads 132 may be positioned closer to each other along the circumference of the object 130 without creating the possibility of unintendedly connecting two pads 132 along the circumference.

A functional zone 134, for example the functional zone 134 with legend symbol "x", can be activated by electrically connecting the two adjacent conductive pads 132A and 132B.

Although a cylindrical embodiment of a keypad is shown with conductive pads 132 and no moving parts, a person skilled in the art will readily appreciate that an embodiment comprising moving parts is also suitable for employing the present invention.

Fig. 19a shows a view of a keyboard according to the present invention, wherein numeral functions are activateable by pressing a common looking key 138 representing a number of functional zones 2a. Further, alphanumeric functional zones 2b are situated between the keys 138. Each key 138 activates, when pressed, four associated switches 6 which are situated under the corners of the keys 138. When activating an alphanumeric functional zone 2b the switches at the corners of the adjacent numeric functional zones 2a are activated.

Figs. 19b - 19d show cross sectional views of a key-like functional zone 138. Under the corners of the key 138, switches 6 are situated. The key 138 and the areas beside it form functional zones 2a and 2b. Use of a suitable combination of hard and flexible material ensures that all associated switches 6 are activated when a functional zone 2a or 2b is activated. Figs. 19e - 19g illustrate possible key shapes and possible switch arrangements in relation to said switch shapes.

When pressing a key 138, all switches 6 situated under the corners of said key 138 are activated and the connected processing device activates the corresponding function. When a functional zone 2b is pressed or touched, the switches 6a adjacent to it are activated, but the switches 6b, not adjacent to the activated functional zone 6a, are not activated.

The elevated portions of the key 138 at the positions where the switches 6 are situated under the key 138 let a user experience the unusual switch arrangement in relation to the usual, common looking keys 138. When a user is later confronted with a keyboard according to the present invention wherein the switches 6 are visible but no keys 138 are present, the user will not be disorientated, but will recognize the switch arrangement.

Claims

C L A I S

1. Data entry system comprising: an input surface, divided into a plurality of functional zones (2) ; a plurality of switches (6) , organized in functional groups of switches (6), each functional group being associated with one of the functional zones (2) , at least one functional zone (2) having an associated functional group of switches (6) comprising at least two switches (6) ; and a processing device (3) for detecting activation of one or more of said switches (6) and for activating a function after activation of a functional group of switches (6) is detected, wherein the plurality of switches (6) is arranged such that each switch (6) of a functional group associated with a functional zone (2) is positioned within a predetermined activation contact area (12) associated with said functional zone (2) , a center of the activation contact area (12) being positioned at a center (20) of said functional zone (2), and wherein the processing device (3) is adapted for detecting activation of a functional group of switches comprising any number of switches.

2. Data entry system according to claim 1, wherein the predefined activation contact area (12) has dimensions substantially equal to a contact area of an activation object and the input surface, the activation object in particular being an adult human finger tip (8) .

3. System according to claim 1 or 2, characterized in that said processing device (3) is adapted for detecting activation of a functional group of switches (6) when, after at least one switch (6) is activated, at least one activated switch (6) is deactivated.

4. System according to any of the preceding claims, wherein the processing device is adapted for detecting activation of a functional zone when, after an associated functional group of switches was activated, any group of switches not associated with said functional zone is activated.

5. System according to claim 4, wherein the group of switches not associated with said functional zone is associated with another functional zone.

6. System according to any of the preceding claims, characterized in that said processing device (3) is adapted for detecting activation of a functional group, when said at least one switch (6) is activated for a predetermined time.

7. System according to any of the preceding claims, characterized in that said switches (6) are pin switches having a cap size, which is smaller than the dimensions of the functional zones (2) , in particular having a cap size of approximately 1-3 mm.

8. System according to any of the preceding claims, characterized in that at least one of the functional zones (2) comprises a switch (6) which is situated in said at least one functional zone (2) , and another at least one of the functional zones (2) lacks a switch (6) which is situated in said other at least one functional zone (2) .

9. System according to claim 8 , characterized in that each switch (6) is associated individually with a functional zone (2) and also is a member of one or more other functional groups, associated with one or more other functional zones (2) .

10. System according to any of the preceding claims, characterized in that a functional zone (2) has more than one associated functional group of switches (6) .

11. System according to any of the preceding claims, characterized in that a division of the input surface in functional zones (2) is a uniform and regular mosaic division of the input surface.

12. System according to any of the preceding claims, characterized in that each of the functional zones (2) is round, oval, square, rectangular, triangular or hexagonal.

13. System according to any of the preceding claims, characterized in that each functional zone (2) has an associated legend symbol (4) .

14. System according to claim 13, wherein a legend symbol (4) is changeable, in particular using an overlay, an underlay or an electronic display.

15. System according to any of the preceding claims, characterized in that said switches (6) are touch or force sensitive sensors.

16. System according to any of the preceding claims, characterized in that said input surface is a single, continuous volume of elastic material.

17. System according to any of the preceding claims, wherein a number of switches (6) is positioned under a key-like functional zone (138), and said switches (6) are also individually activateable .

18. System according to any of the preceding claims, characterized in that the input surface is provided with molded key caps, grooves, bumps or dots defining the boundaries or other parts of the functional zones (2) , or with back lighting of legend symbols, to provide tactile or visual feedback.

19. System according to any of the preceding claims, characterized in that the processing device (3) is an electronic circuit.

20. System according to claim 19, wherein each switch comprises a conductive activation pad electrically connected to an input of the processing device, the activation pads being spaced apart, wherein a functional zone may be activated by electrically connecting the activation pads of at least two switches .

21. System according to claim 20, wherein a plurality of activation pads is connected to one input of the processing device.

22. System according to claim 20 or 21, wherein an electrical connection between at least two activation pads may be made by a finger simultaneously touching said at least two activation pads.

23. System according to claim 19 or 20, wherein a layer of electrically conducting material is positioned over said activation pads and wherein applying a pressure on said electrically conducting layer may electrically connect two or more activation pads.

24. System according to any of claims 1 - 19, wherein the system comprises a. a first layer having a first surface having conductive paths and insulative paths between said conductive paths; b. a second layer being flexible and having a first surface having conductive paths and insulative paths between said conductive paths, the second layer having a second surface having activation areas positioned thereon opposite to the conductive paths on said first surface of the second layer; said first surface of the first layer being positioned opposite to the first surface of the second layer, the surfaces being spaced apart such that applying a pressure on an activation area on the second surface of the second layer electrically connects a unique combination of a conductive path of the second layer and a conductive path of the first layer, the conductive paths of the first and the second layer being connected to inputs of the processing device.

25. System according to claim 24, wherein the first layer and second layer are identical layers .

26. System according to claim 24 or 25, wherein a third layer of an electrically conducting material is positioned between the first and the second layer of flexible sheet material, wherein applying a pressure on an activation area on a second surface of the first or the second layer electrically connects said third layer with a conductive path on the first layer and with a conductive path on the second layer.

27. Method for detecting activation of at least two switches comprised in a data entry system, each switch comprising an activation pad electrically connected to an input of a processing device, the method comprising a step of detecting an electrical connection between at least two inputs of the processing device.

28. Method according to claim 27, wherein the data entry system further comprises a conductive material, which may make an electrical connection between the activation pads of at least two switches, and which is electrically connected to an input of the processing device, the method comprising detecting an electrical connection between the conductive material and at least one conductive path of the first layer and at least one conductive path of the second layer.

29. Use of a compact data entry system according to any one of claims 1 - 26 in a portable electronic device, in particular in a hand-held computer, a telephone, a dictionary or translator, a personal information manager, a calculator, a labeler or a watch.

30. Use of a data entry system according to any one of claims 1 - 26 in a convex, in particular cylindrical object, in particular a pointing device, a pencil or a pen.