HK1160691B - External keyboard - Google Patents

Description

External keyboard

The present application is a divisional application of an invention patent application having an application date of 2007, 2/2, application number of 200780004208.9, and an invention name of "external keyboard".

Technical Field

The present invention relates to external keyboards, for example, to external keyboards operable to interface with a digital device spatially located adjacent thereto. Furthermore, the invention also relates to a method of communicating information from such external keyboards to their associated devices in proximity thereto. Furthermore, the invention also relates to a software product executable on said digital device enabling said device to communicate with such an external keyboard. Additionally, the present invention relates to a digital system comprising a digital device operable to be coupled to an external keyboard.

Background

Current digital devices include, for example, cellular telephones, mobile telephones, digital personal organizers, and Personal Digital Assistants (PDAs). An example of a mobile telephone, generally indicated at 10, is illustrated in fig. 1 and 2. The phone 10 comprises a display 20, for example implemented using Liquid Crystal Display (LCD) technology, for displaying information, such as text and images, to a user of the phone 10. Moreover, the phone 10 further comprises a keypad, generally indicated at 30, for entering data into the phone 10, such as numerical data for dialing numbers and text for a Special Messaging Service (SMS). Other components of the telephone include a microphone 40 and a speaker 50 coupled to a data processor 60. Moreover, the telephone 10 also includes an antenna 70 coupled to radio frequency circuitry 80 for enabling the telephone 10 to communicate wirelessly with a mobile telephone network (not shown), which in turn is coupled to the data processor 60 of the telephone 10; such communication with the mobile telephone network is effected at radio communication frequencies of the order of 1 GHz. Alternatively, the phone 10 can also communicate directly with other devices in the spatial vicinity of the phone 10 via a wireless interface 90 coupled to the data processor 60, for example via proprietary bluetooth or a similar protocol in the range of a few meters, i.e. at a radio communication frequency of 13.56 MHz. Other such devices include, for example, headsets with earphones and microphones that enable "hands-free" operation of the telephone 10.

A Personal Digital Assistant (PDA) is generally similar to the mobile telephone 10 described above, except that components that enable the PDA to communicate with the mobile telephone network are omitted. However, it is conventional practice to operate PDAs to communicate locally in a wireless manner, for example by using the bluetooth protocol to communicate with other digital devices, for example with Personal Computers (PCs) and laptops, for example for data synchronisation purposes.

Digital devices such as mobile phones and personal digital assistants have become increasingly more complex over time as manufacturers include more powerful data processors and more memory therein. Moreover, such devices have now reached a sufficient level of maturity so that software applications, written in Java or javascript, for example, may be downloaded therein to perform specific functions, which may optionally be performed in response to user commands. For example, some mobile phones include text editing software to assist in preparing SMS messages, which may be stored in a data store included with the phone.

In order to provide mobile telephone products and personal digital assistant products that meet the requirements of modern users, manufacturers of these products have sought to produce increasingly more compact digital devices. As a result of this miniaturization, the aforementioned keypad 30 has evolved into one or more of the following: including more keys that can be pressed by the user, using keys of a smaller physical size, using multifunction keys. Moreover, a further consequence of this miniaturization is that the aforementioned display screen 20 has an increased pixel resolution to present finer detail. This development of the keyboard 30 and the display 20 has led to the problem of reduced eyesight and a lack of finger agility experience when a user is working with modern digital devices such as mobile phones and personal digital assistants. To solve this problem, it is current practice to provide the user with a click pen for pressing the micro-keys and also with an optical magnifier, for example a magnifying glass for viewing the micro-display. Also, the multifunction key allows a reduction in the total number of required keys, but makes the input of user data laborious unless the user has excellent finger agility.

In the foregoing, local digital communication by bluetooth or a similar protocol is described. Other types of devices that use this protocol include Radio Frequency Identification Devices (RFID). Near Field Communication (NFC) is also well known. NFC technology is based on a combination of contactless identification technology like RFID and a variety of connection technologies. Standards have been established to define how devices using these techniques interoperate to form peer-to-peer (P2P) networks. NFC operates in a frequency range of the order of 13.56MHz over a distance of typically a few centimeters. Moreover, to date, much effort has been made in standardizing NFC technology; such standards include ISO 18092, ISO21481, ECMA (340, 352 and 356) and ETSI TS 102190. Furthermore, this NFC technology is also compatible with the contactless infrastructure of standard ISO 14443A based smart cards, including philips 'MIFARE technology and sony's FeliCa card.

In the published international PCT application with application number PCT/US99/29362(WO 00/36849), a hand-held passive remote control programmer for a microprocessor controlled Radio Frequency Identification (RFID) reader of the inductive type is described. The reader comprises a rigid molded housing including an antenna represented by a capacitor C1 and an inductor L1, and a plurality of application specific integrated circuit RFID transponder tags IC1 through IC 16. Each transponder tag has a unique code associated with it. Moreover, the housing also includes a keypad having a plurality of keys. Each key is selectively operated to directly connect a respective one of the transponder tags to the antenna so as to provide power to the selected tag by induction in the radio frequency sensitive field of the RFID reader. The RFID reader is thereby able to determine, in operation, when one or more of the keys is depressed by a user of the remote control programmer. Programming instructions stored in the RFID reader identify each unique tag as representing actuation of a particular key on the remote programmer keyboard. The RFID reader recognizes the actuation of a particular key or key sequence of the programmer as a programming instruction for the reader's microprocessor.

Other remote-controlled wireless keyboards are well known. For example, in U.S. patent No. 6,133,833, a wireless keyboard or keypad remotely powered by a radio frequency exciter/receiver is described. The wireless keyboard is suitable for use in a radio frequency identification system. Also, the wireless keyboard and the exciter/receiver communicate by electrostatic or electromagnetic radiation without wires. The wireless keyboard has no integrated power supply. It can be asserted that the wireless keyboard can be easily added or retrofitted to existing radio frequency identification systems. The keyboard has a plurality of manually actuated keys or control members. Pressing a key or button results in the generation of a predetermined response signal associated with that key or button. The response signal relates to the operation of a device or system associated with the exciter/receiver. Implementations of the wireless keyboard include directly coupling an antenna including an inductor and a capacitor to an array of RFID devices that are selectively connected to the antenna in response to user actuation of a key or button.

Such a wireless keyboard and passive remote control as described above has a relatively large physical size compared to a mobile phone or a personal digital assistant, which large size represents a technical problem. Moreover, such keyboards and controllers are often implemented such that a mobile phone or Personal Digital Assistant (PDA) cannot be coupled well enough to provide power to the keyboard or passive controller.

Disclosure of Invention

It is a first object of the present invention to provide a wireless keyboard that is capable of operating with mobile telephones and/or personal digital assistants and similar types of miniature digital devices.

It is a second object of the present invention to provide a wireless keyboard that is compact when stored, but is operable to occupy a sufficiently large size when expanded to facilitate easier entry of data by a user.

It is a third object of the present invention to provide a wireless keyboard that is designed so that it can interoperate with a number of different types of mobile phones and personal digital assistants.

The invention, as defined by the appended claims, is capable of solving one or more of these objects of the invention.

According to a first aspect of the present invention there is provided a keypad comprising a plurality of user operable alphanumeric keys, the keypad comprising one or more identification devices associated with the user operable keys, and wherein, in response to user actuation of one or more of the user operable keys, the one or more identification devices are operable to selectively communicate with a numeric apparatus located adjacent the keypad,

the method is characterized in that:

(a) the keyboard comprises a flexible substrate for enabling the keyboard to be folded and/or rolled into an inactive state of non-use and unfolded and/or unrolled into an active state of use in communication with the digital device;

(b) the keyboard is operable to communicate with the digital device through near field magnetic and/or electrostatic coupling when in proximity to the digital device; and

(c) the keyboard comprises an intermediate resonant circuit for interfacing between the one or more identification devices and the digital apparatus, wherein the resonant circuit comprises an element spatially disposed to cover a first area on the digital apparatus in use and to cover a second area coupled to the one or more identification devices in use to couple signals therebetween.

The invention has the advantages that: the combination of the keyboard being flexible, using near field communication and being efficiently coupled through an intermediate resonant circuit provides benefits to the keyboard when data input is performed to the digital device.

Optionally, in the keyboard, the intermediate resonant circuit is operable to exhibit a Q factor greater than 1 for providing signal enhancement to enable the one or more identification devices to derive energy from power delivered thereto by the intermediate resonant circuit. Such a high Q factor provides for more energy efficient communication between the digital device and the keyboard, for example, enabling the keyboard to obtain energy from the digital device, thereby avoiding the need to include a battery or the like within the keyboard. More optionally, the Q factor is beneficially in the range of 10 to 100.

Optionally, in the keyboard, the intermediate resonant circuit is coupled only to communicate the alternating signal induced therein to the one or more identification devices and the digital apparatus. The need for a physical electrical connection between the keyboard and the digital device is avoided, making it easier to quickly couple the keyboard into communication with the digital device, and also making it more reliable in operation, especially in wet and/or corrosive environments.

Optionally, the substrate of the keyboard comprises a plurality of layers bonded, laminated and/or molded together. This manufacturing method enables the keyboard to be easily manufactured using automated production equipment. More optionally, the keyboard is manufactured in a roll form via multiple layers that are bonded, laminated, and/or molded together during the manufacture of the keyboard.

Optionally, in the keyboard, the plurality of layers comprises at least one of: polymeric insulating layers, conductive layers, printed electronic polymer layers, surface mount electronic chip components, surface mount passive components.

Optionally, in order to make the keyboard more useful in conjunction with such digital devices when such digital devices have a miniature shape, the keyboard further comprises a pixel display having an associated display driver for receiving data from the digital device through the intermediate resonant circuit in operation, the pixel display for presenting visual information to a user of the keyboard in operation. More optionally, the pixel display is implemented with an organic printable electronic element operable to bend when the keyboard is manipulated between its inactive folded state and its active unfolded state, for example for economy and convenience of production.

Optionally, in the keyboard, the first region is smaller in area than the second region. Such proportions make the intermediate resonant circuit of the keyboard less susceptible to detuning in use in response to different types of digital devices used in conjunction with the keyboard.

Optionally, in the keyboard, the first region is arranged to have an area substantially corresponding to an area provided on the keyboard for accommodating the digital device in operation. This arrangement of the keyboard may be more securely operatively coupled to the digital device when the digital device is placed adjacent to the keyboard and the keyboard is used in its active unfolded state.

Optionally, the intermediate resonant circuit is operable to exhibit a resonant frequency of substantially 13.56MHz in the keyboard, for example, to comply with various international standards for RFID integrated circuits.

Optionally, in the keyboard, at least one of the one or more identification devices is operable to multiplex a plurality of keys of the keyboard for monitoring user actuation thereof during operation of the keyboard. This multiplexing can reduce the number of identification devices that need to be fitted into the keyboard during its manufacture, thereby potentially reducing its manufacturing cost.

Optionally, for ease of use to enable left and right hands for data entry into the keyboard, the first region for receiving the digital device is arranged substantially centrally of the keyboard when the keyboard is in use in its active expanded state.

Optionally, alternatively, the first region of the keyboard is arranged substantially asymmetrically towards a peripheral edge of the keyboard when the keyboard is in use in its active unfolded state.

Optionally, the keyboard has its keys selectively spatially arranged to assist with one or more of: entering alphanumeric data into the digital device, playing a game executed in communication with the digital device. This arrangement of the keyboard enables it to be optimally suited for a user to perform a particular type of data input to the digital device.

Optionally, the keyboard includes a power source therein, the power source operatively coupled to provide energy to the one or more identification devices if insufficient power is available to provide energy to the one or more identification devices coupleable from the digital apparatus through the intermediate resonant circuit. This implementation of the keyboard enables the keyboard to be used with a wider range of digital devices, some of which may not be able to radiate sufficient energy to power the keyboard.

According to a second aspect of the present invention there is provided a keypad comprising a plurality of user operable alphanumeric keys, the keypad comprising one or more identification devices associated with the user operable keys, and wherein, in response to user actuation of one or more of the user operable keys, the one or more identification devices are operable to selectively communicate with a numeric apparatus located adjacent the keypad,

the method is characterized in that:

(a) the keyboard comprises a flexible substrate for enabling the keyboard to be folded and/or rolled into an inactive state of non-use and unfolded and/or unrolled into an active state of use in communication with the digital device;

(b) the keyboard is operable to communicate with the digital device through near field magnetic and/or electrostatic coupling when in proximity to the digital device; and

(c) the keyboard further includes a pixel display having an associated display driver for receiving data from the digital device in operation, the pixel display for presenting visual information to a user of the keyboard in operation.

Optionally, the keyboard comprises an intermediate resonant circuit for interfacing between the one or more identification devices and/or the display driver and the digital apparatus.

The keyboard according to the second aspect of the invention is implemented such that the pixel display is implemented using an organic printable electronic element operable to bend when the keyboard is manipulated between its inactive folded state and its active unfolded state.

According to a third aspect of the present invention there is provided a method of coupling a keypad, the keypad comprising a plurality of user operable alphanumeric keys and communicating with a digital apparatus positioned adjacent the keypad, the keypad comprising one or more identification devices associated with the user operable keys, the one or more identification devices being operable to selectively communicate with the digital apparatus in response to user actuation of one or more of the user operable keys,

characterized in that the method comprises the steps of:

(a) manufacturing the keyboard comprising a flexible substrate for enabling the keyboard to be folded and/or rolled into an inactive state of non-use and unfolded and/or unrolled into an active state of use in communication with the digital device;

(b) communicating with the digital device from the keyboard through near field magnetic and/or electrostatic coupling when in proximity to the digital device; and

(c) interfacing between the one or more identification devices and the digital apparatus using an intermediate resonant circuit in the keyboard, wherein the resonant circuit comprises elements spatially arranged to overlie a first region on the digital apparatus in use and to overlie a second region coupled to the one or more identification devices in use to couple signals therebetween.

According to a fourth aspect of the present invention there is provided a software product stored and/or transmitted on a data carrier, the software product being executable on computing hardware of a digital apparatus for implementing a method according to the third aspect of the present invention. The software product can be transferred to the digital apparatus by means of signals operable as data carriers and/or by means of physical data carriers.

It will be appreciated that features of the invention are susceptible to being combined in any combination without departing from the scope of the invention as defined by the accompanying claims.

Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the following drawings, in which:

FIG. 1 is a schematic diagram of a known prior art mobile telephone, also known as a cellular telephone;

fig. 2 is a schematic view of constituent parts constituting the mobile phone of fig. 1;

FIG. 3 is a schematic view of a first embodiment of the present invention, namely an external keyboard implemented using a flexible substrate;

FIG. 4 is an illustration of the mobile telephone of FIG. 1 positioned on the external keyboard shown in FIG. 3;

FIG. 5 is an illustration of the internal components of the external keyboard illustrated in FIG. 3;

FIG. 6 is an illustration of a Radio Frequency Identification Device (RFID) integrated circuit included within the external keyboard shown in FIG. 3;

FIG. 7 is an illustration of an alternative embodiment of the external keyboard of FIG. 3, including an internal power source, such as a battery;

FIG. 8 is a schematic diagram of an implementation of the external keyboard shown in FIG. 3, wherein the area of the keyboard for coupling to the mobile telephone covers only a sub-portion of the interface area provided by the mobile telephone of FIG. 1 when placed on the keyboard in operation;

FIG. 9 is a schematic diagram of an implementation of the external keyboard shown in FIG. 3 in which the area of the keyboard for coupling to the mobile telephone covers substantially only the entire interface area provided by the mobile telephone of FIG. 1 when placed on the keyboard in operation;

FIG. 10 is a schematic diagram of an implementation of the external keyboard shown in FIG. 3, in which a multiplexed Radio Frequency Identification Device (RFID) integrated circuit is used to interface with a plurality of user actuated keys;

FIG. 11 is a schematic diagram of the internal components of the multiplexed Radio Frequency Identification Device (RFID) integrated circuit used within the keyboard shown in FIG. 10;

FIG. 12 is a schematic diagram of an implementation of the external keyboard of FIG. 3 in combination with a flexible electronic display;

FIG. 13 is a schematic diagram of a simplified implementation of the keyboard of FIG. 3, suitable for the entry of digital data into the mobile telephone or similar device illustrated in FIG. 1;

FIG. 14 is a schematic diagram of a simplified implementation of the keyboard of FIG. 3, suitable for use in conjunction with the mobile telephone or similar device illustrated in FIG. 1 for game play activities;

FIG. 15 is a schematic diagram of a simplified implementation of the keyboard of FIG. 3 suitable for communicating with a small subset of defined persons using the mobile phone or similar device illustrated in FIG. 1;

16a, 16b, 16c are illustrations of various alternative connection arrangements for coupling Radio Frequency Identification Device (RFID) integrated circuits in the keyboard of FIG. 3, and variations thereof shown in other figures;

FIGS. 17a and 17b are schematic diagrams of an implementation of the external keyboard shown in FIG. 3, which is implemented using electrostatic capacitive coupling therein in operation; and

FIG. 18 is a schematic diagram of a capacitive coupling switch suitable for use in implementing the external keyboard shown in FIG. 3 using electrostatic capacitive coupling.

In the drawings, numbers with associated arrows are generally used to indicate given items. Also, underlined numbers are used to indicate the items that they cover. A number associated with a connecting line is used to indicate an item where an end of the connecting line remote from the number terminates.

Detailed Description

In general, the present invention relates to an external keyboard that can interoperate with a compact digital device through near field wireless communication; such compact digital devices include, but are not limited to, one or more of mobile telephones, Personal Digital Assistants (PDAs), and the like. Due to the flexible structure of the external keyboard, the external keyboard in its initial inactive state can be folded or rolled up when not in use. Furthermore, the external keyboard can be deployed or expanded to its second active state, deploying it for use. Further optionally, the external keyboard comprises an area thereof designated for placing the compact digital device thereon, thereby enhancing efficient coupling of near field radiation from the compact digital device to the remote keyboard and from the remote keyboard to the compact digital device.

Referring to FIG. 3, an embodiment of an external keyboard according to the present invention is generally indicated by 100 a. The external keyboard 100a is manufactured to include a flexible substrate 110. When not in use, the substrate 110 can be at least one of folded and rolled for storage. Alternatively, when deployed, the external keyboard 100a can be unfolded or unfolded into a substantially planar state suitable for placement on a substantially planar bearing surface, such as on an upper surface of a table, for enabling user access to actuate keys of the keyboard 100a, such as keys 120. This deployment of the keyboard 100a to a substantially planar state is also illustrated in fig. 4, wherein an area 130 is arranged to receive the compact digital device, such as a mobile phone or Personal Digital Assistant (PDA), indicated by 10.

The keyboard 100a illustrated in fig. 3 and 4 optionally has a thickness to its substrate 110 in the range of 2mm to 5mm, and the planar dimensions in use optionally include a length from left to right in the range of 15cm to 30cm, and a depth from front to back in the range of 10cm to 20 cm. However, as will be explained later, the keyboard 100a may be implemented to have other physical dimensions. Moreover, while the area 130 for receiving the mobile telephone 10 is illustrated in FIGS. 3 and 4 as being substantially toward the center of the keypad 100a, it should be understood that other implementations of the keypad include the area 130 offset to one side thereof.

The substrate 110 of the keyboard 100a is preferably made of a flexible material, for example made of one or more of the following materials: silicone rubber, a film of plastic material including a metal conductor thereon or therein, a film of plastic material on which electronic components are printed and/or bonded, and the like. Alternatively, a film of plastic material is made of Kapton (Kapton) polyimide film, acetate board, or the like; "Cappton" is a registered trademark of DuPont. Moreover, the substrate 110 optionally further includes surface mount electronic components such as ceramic capacitors, resistors, and RFID integrated circuits. Conveniently, the RFID integrated circuit is of modern design and is operable to comply with the aforementioned standards for RFID devices. The substrate 110 may be formed by molding, bonding, and/or lamination techniques; for example, multiple pieces of plastic material and/or silicone (silicone) may be laminated, bonded, and/or molded together on a continuous substrate and subsequently cut into individual keypads 100 a. This continuous method of manufacturing in the form of so-called "roll good" enables the keyboard 100a to be rapidly mass-produced in automated manufacturing equipment.

The structure of the external keyboard 100a will now be further explained with reference to fig. 5. The keyboard 100a includes an inductor 140 implemented as a conductive loop and including one or more conductive loops. Optionally, the inductor 140 includes only a single conductor turn. The inductor 140 connects a capacitor and a resistor, collectively indicated at 150, in series. The capacitor and resistor 150 are operable to form a resonant circuit with the inductor 140, optionally having a Q factor in the range of 10 to 100, and more preferably in the range of 20 to 50. Although the high Q factor of the resonant circuit, close to 100, makes it possible to couple the keypad 100a very efficiently to the mobile phone 10, the tuning of the resonant circuit becomes more heavily dependent on the performance of the ferromagnetic elements present within the mobile phone 10. Conversely, a Q-factor below 10 is sub-optimal because the coupling of near-field radiation from the mobile phone 10 is not as efficient, although the tuning of the resonant circuit is less important at this time. Thus, it has been found that a Q factor of the resonant circuit in the range of 20 to 50, more preferably 40, is a desirable viable compromise of the keyboard 100 a.

The inductor 140 is preferably fabricated by a metal film formed on an insulating layer, such as kapton polyimide polymer film (kapton polyimide polymer film). Also, the resistor and capacitor 150 may optionally be implemented as a surface mount component that is attached to the inductor 140. Alternatively, the capacitor and resistor 150 is implemented as a thin film of printed and/or laminated elements, as will be explained in more detail later.

When the mobile phone 10 is placed on the area 130, the resonance circuit formed by the inductor 140 together with the capacitor and its resistor 150 are arranged to have a resonance frequency of substantially 13.56MHz, as illustrated in fig. 4. Moreover, the aforementioned Q-factor of the resonant circuit is selected so that different types of digital devices placed in the area 130 do not detune the resonant circuit formed by the inductor 140 and the capacitor 150 to the extent that the keyboard 100a is inoperable.

As shown in fig. 5, the inductor 140 surrounds the region 130 and also surrounds an additional region 160 adjacent to the region 130. The sum of the regions 130, 160 depicts the total area around which the inductor 140 is magnetically surrounded. By providing additional region 160 having a larger area relative to region 130, the resonant circuit including the inductor 140 is not easily detuned from the frequency of 13.56MHz when different types of digital devices including ferromagnetic elements are placed on region 130.

As shown in fig. 5, the keyboard 100a further includes one or more RFID circuits, such as the RFID circuit indicated by 200; optionally, the keyboard 100 comprises a plurality of such RFID circuits 200. Each circuit 200 comprises an inductor 210, said inductor 210 at least partially covering said additional area 160 and thus being magnetically coupled to said inductor 140 in operation. Moreover, each circuit 200 includes one or more RFID integrated circuits 220, the RFID integrated circuits 220 being respectively coupled in series with one or more corresponding switches 240 as shown; each circuit 200 optionally includes a plurality of RFID integrated circuits 220. In operation, as indicated by arrow 250, actuation of the switch 240 causes the switch 240 to change from a non-conductive state to a conductive state to connect its RFID integrated circuit 220 across the inductor 210 and thus communicate with the resonant circuit that includes the inductor 140.

The RFID integrated circuit 220 is optionally a proprietary device, as shown in fig. 6, which includes a rectifying circuit 270 for supplying power to a digital unit 280 of the integrated circuit 220 through an interrogation signal coupled from a mobile phone 10 placed on the area 130; the mobile phone 10 communicates through the resonant circuit including the inductor 140 and then through the inductor 210 to the RFID integrated circuit 220 at a frequency of substantially 13.56 MHz. In this manner of operation, the keypad 100a can be operated using power supplied solely from the mobile telephone 10, thereby enabling the keypad 100a to be implemented without any power source therein, such as without any form of battery or the like therein. This implementation is attractive to the user of the keyboard 100a because it avoids the need for the user to be concerned about situations in which the keyboard 100a malfunctions due to a battery drain occurring therein.

Advantageously, inductor 210 is implemented to have a plurality of turns, for example in the range of 5 to 100 turns. Also, inductor 210 is preferably implemented with one or more of the following: thin film printing, appropriate spatial arrangement, or etched or vacuum deposited conductors forming inductor 210. Alternatively, the inductor 210 may be fabricated using an insulated bobbin, such as an enameled copper wire with a diameter of 0.1 mm. Thus, the inductor 140 in combination with the one or more inductors 210 effectively constitute a transformer that facilitates the generation of a rectified enough potential within the RFID integrated circuit 220 so that they are operable when a user actuates their corresponding key on the keyboard 100 a.

The one or more RFID integrated circuits 220 are preferably proprietary silicon devices mounted as bare dies (die) inside the keyboard, for example by gold ball bump bonding. Alternatively, the RFID integrated circuit 220 may be implemented in the form of a printed film using an organic polymer capable of forming an organic semiconductor device. The fabrication of electronic circuits using printable semiconducting polymeric inks has been previously described, for example, in published international PCT patent applications PCT/GB2004/000433(WO 2004/0704669) and PCT/GB2003/005435(WO2004/055920), the contents of which are hereby incorporated by reference, to illustrate the operation of the present invention.

Referring next to fig. 7, an alternative embodiment of a keyboard in accordance with the present invention is indicated generally at 100 b. The keyboard 100b schematically depicted in fig. 7 is generally similar to the aforementioned keyboard 100a depicted in fig. 5, except that the keyboard 100b can optionally be implemented to include a power source within its interior. The power source is advantageously a battery comprising one or more cells, as shown in fig. 7; the battery is indicated by 300. The battery 300 may be a constituent part added and sealed therein during the manufacture of the keypad 100 b. Alternatively, the battery 300 may be user accessible and optionally user serviceable, i.e., replaceable by the user. Alternatively, the battery 300 is a miniature rechargeable device. More alternatively, the battery 300 may be implemented by a thin film printing technique. Advantageously, switches 310 associated with the keys of the keypad 100b shown in fig. 7 are provided with a plurality of sets of contacts, such as a first set of contacts S1 for connecting a given RFID integrated circuit 220 to the battery 300 (which is used to provide operating power to the integrated circuit 220), and a second set of contacts S2 for connecting the given RFID integrated circuit 220 to its associated inductor 210 and thereby to the mobile phone 10 or similar device placed over the area 130 via the resonant circuit including the inductor 140.

In fig. 8, an illustration of the internal components of the keyboard 100a shown in fig. 3 is shown. The additional area 160 of the inductor 140 over which the inductor 210 is overlaid has a much larger area, e.g. more than 3 times the area, than the area 130 over which the mobile phone 10 or similar device is overlaid in operation. As previously mentioned, such an area ratio is beneficial for making the tuning circuit, which is constituted by the inductor 140 coupled to the capacitor and its resistor 150, less prone to becoming detuned in response to ferromagnetic or paramagnetic elements provided in the mobile phone 10 or similar device on which the mobile phone 10 or similar device is placed over the area 130.

In fig. 9, an alternative embodiment of the keyboard is indicated by 100 c. The keypad 100c is similar to the keypad 100a shown in fig. 8, except that when the mobile telephone 10 or similar device is placed on the keypad 100c, the area 130 is enlarged so that it encompasses substantially the entire area of the mobile telephone 10 or similar device. This implementation makes the resonant circuit containing inductor 140 and capacitor and resistor 150 more susceptible to detuning from 13.56MHz, but still results in more excitation energy being coupled in operation between the RFID integrated circuit 220 and the mobile phone 10 or similar device placed over area 130. In fig. 9, region 130 is substantially similar in area to additional region 160 overlying inductor 210 described previously.

To simplify the manufacture of the external keyboard 100 by reducing the number of RFID integrated circuits 220 required therein, the keyboard is optionally implemented as shown in fig. 10, wherein the keyboard is generally indicated by 100 d. In the keyboard 100d, an RFID integrated circuit indicated by 400 is included, which includes the aforementioned rectifying circuit 270 and the aforementioned digital unit 280. The RFID integrated circuit 400 further includes a multiplexer 410, as shown in fig. 10 and 11, such that the RFID integrated circuit 400, when activated, scans a plurality of switches, indicated at 420, to determine which of the switches 420 is depressed. Moreover, the RFID integrated circuit 400 is operable when the mobile phone 10, alternatively a Personal Digital Assistant (PDA) or similar device, is placed on the area 130 of the keypad 100d shown in FIG. 10, and power is supplied from it to the RFID integrated circuit 400. When energized, the RFID integrated circuit 400 scans the switch 420 and through its associated inductor 210 then back through the inductor 140 to the mobile phone 10 placed on the area 130. Optionally, a connector is provided on the RFID integrated circuit 400 that is unique to each of the switches 420. Alternatively, or in addition, the RFID integrated circuit 400 is provided with a matrix multiplexing arrangement of columns and rows as shown to reduce the number of connectors required from the RFID integrated circuit 400 to the switch 420. More optionally, power is supplied to the RFID integrated circuit 400 from a battery included inside the keyboard 100d, as shown in fig. 10. Beneficially, the RFID integrated circuit 400 is operable to derive its power from energy coupled from the mobile telephone 10 via the inductors 140, 210, and is optionally operable to switch only to power derived from the battery when the power provided by the mobile telephone 10 placed on the area 130 is insufficient.

Referring next to fig. 12, a keyboard in accordance with the present invention is indicated generally at 100e and is similar to keyboard 100a except that the keyboard 100e additionally includes an electronic display 510 connected to an electronic driver unit 500, which is further connected to an inductor 210 for coupling into inductor 140, as shown in fig. 12. Advantageously, the electronic display 510 is manufactured as a flexible region on the keyboard 100e using an electronic printing device, thereby enabling the keyboard 100e to include such a flexible display so that it can be folded or rolled up for storage when not in use. Also, the display 510 is optionally manufactured using the techniques described in published U.S. patent application No. US 2006/0181751, which relates to using electric fields to manipulate charged bodies to create visual contrast for presenting visual images; the contents of this patent application are hereby incorporated by reference to describe embodiments of the present invention. Alternatively, the electronic driver unit 500 is implemented as an integrated circuit assembled as a surface mounted component inside the substrate 110, or as a printed electronic circuit as previously described. Thus, the mobile telephone 10 or Personal Digital Assistant (PDA) or similar device disposed over the area 130 is operable, via the inductors 140, 210, to communicate display information, such as text and images, to the electronic display 510 at a carrier frequency of 13.56MHz so that a user may present the visual information using a larger spatial dimension than is possible via the display 20 of the mobile telephone 10 shown in FIGS. 1 and 2. The electronic driver unit 500 is operable to receive a stream of image data and appropriately multiplex the image data in driving the pixel cells of the electronic display 510. The power for operating the electronic driver unit 500 is preferably derived from the mobile phone 10 or similar device placed on the area 130, as depicted in fig. 4. Implementing the keyboard 100 in the manner shown in fig. 12 advantageously enables the problem of the display 20 and the keyboard 30 being too small for comfortable use for a longer period of use, for example for a few hours in a row.

The keyboard 100a shown in fig. 3 can be implemented in a simpler form as shown in fig. 13. The keyboard shown in fig. 13 is indicated by 100f and is based on the implementation of the aforementioned keyboards 100a to 100 e. The keypad 100f has its region 130 for receiving the mobile telephone 10 offset to the left hand side of its substrate 110 as viewed by its user in operation; optionally, for the keyboard 100f, a region 130 may alternatively be included on the right hand side of the substrate 110, as viewed by the user in operation. Also, the keys 240 in fig. 13 are specifically arranged to facilitate dialing upon a telephone call, preparation of an SMS message, and for general numeric data entry. This form also enables larger keys 240 to be employed for the keyboard 100f relative to the implementation of the keyboard 100a in fig. 3, for example to make it easier for a person lacking good muscle movement control to use the keyboard 100f in fig. 13. Alternatively, this form makes the substrate 110 of the keyboard 100f shown in fig. 13 smaller in size than the keyboard 100a shown in fig. 3 to improve its portability and to easily meet its storage requirements when not in use.

Alternatively, the keyboard 100 shown in FIG. 3 may be implemented in a simpler form, generally indicated by 100g, shown in FIG. 14. The keyboard 100g shown in fig. 14 has an area 130 for receiving the mobile telephone 10, Personal Digital Assistant (PDA) or similar device, the area 130 being located on the left hand side of the substrate 110 as viewed by a user in operation; optionally, a region 130 may alternatively be included on the left hand side of the substrate 110, as viewed by the user in operation. Moreover, the keys 240 of the keypad 100g of FIG. 14 are particularly arranged to facilitate control of the playing of interactive games and the like on the mobile telephone 10, Personal Digital Assistant (PDA) or the like, which mobile telephone 10, Personal Digital Assistant (PDA) or the like is positioned in use on the area 130.

Alternatively, the keyboard 100a shown in FIG. 3 may be modified to be implemented in a simpler form, generally indicated by 100h, shown in FIG. 15. The keyboard 100h shown in fig. 15 has an area 130 for receiving the mobile telephone 10, Personal Digital Assistant (PDA) or similar device, which is located on the left-hand side of the substrate 110 as viewed by a user in operation; optionally, a region 130 may alternatively be included on the left hand side of the substrate 110, as viewed by the user in operation. Also, the keys 240 of the keypad 100h of fig. 15 are specifically arranged to facilitate dialing of particular telephone numbers, for example, dialing of close relatives, such as mom, dad, brother and/or sister. In operation, actuation of one or more of the switches 240 of the keypad 100h by a user causes a message to be transmitted to the mobile telephone 10 placed on the area 130 of the keypad 100h to invoke a pre-programmed number entered into the telephone 10. The keyboard 100h of fig. 15 is particularly useful for young children who have difficulty learning and typing long digital streams, and for elderly people with impaired cognitive abilities.

In the previously described versions of the keyboards 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, the RFID integrated circuit 220 together with its switch 240 can be implemented in a variety of ways. In fig. 16a, the RFID integrated circuit 220 is connected in series with its aforementioned inductor 210 and is coupled to two contacts of its switch 240, which are connected to each other by a single movable conductor 600 when the switch 240 is actuated by a user. Optionally, the inductor 210 is provided with a tuning circuit 610, such as a tuning capacitor optionally in parallel with a Q-factor determining resistor, for tuning to 13.56MHz, thereby preventing interference at frequencies other than substantially 13.56MHz from propagating to the RFID integrated circuit 220. In fig. 16b, the RFID integrated circuit 220 is shown optionally incorporated in a button, i.e. a key, of the switch 240. In fig. 16c, the RFID integrated circuit 220 together with its inductor 210 are shown both integrated into a button, i.e. a key, of the switch 240; this implementation has the benefits that: it enables the keys 120 of the keyboard 100 to fit more closely together while maintaining their exposed user accessible top surface area large for ease of use.

In the foregoing, the near field magnetic coupling of the mobile phone 10 or similar device placed on the area 130 shown in fig. 4 to the keypad 100a is illustrated. It should be understood, however, that a corresponding electrostatic, i.e. capacitive, coupling is also possible. When the keyboards 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h are implemented in this manner, the circuit configuration thereof can be implemented in the form shown in fig. 17a and 17 b.

In fig. 17a, a patch antenna 900 is provided in the phone 10; the patch antenna 900 is conveniently implemented as a conductive plate. Furthermore, the substrate 110 of the electrostatically implemented keypad has a floating conductive plane 910, e.g. a laminated metal layer, which in operation constitutes a capacitor C1 with the patch antenna 900. The substrate 110 also includes a conductive ground plane (earth plane)920E laminated or otherwise incorporated therein. The floating conductive plane 910 forms a capacitor C2 with the aforementioned conductive ground plane 920E. Adjacent over the area of the floating conductive plane 910 is an electrode plane 930 which forms a capacitor C3 with the floating conductive plane 910. Also, the electrode plane 930 is connected to the conductive ground plane 920E through an inductor L. The inductor L is an additional surface mount component inside the substrate 110 or is fabricated by appropriately forming conductive traces (tracks). The capacitors C2 and C3 constitute a series capacitor indicated by CR, having a capacitance defined by equation 1 (eq.1):

also, the series capacitor CR constitutes a resonance circuit having a resonance frequency f defined by equation 2(eq.2) using the inductor L₀：

The frequency f is set, for example, by suitably selecting the inductance value for the inductor L₀Adjusted to substantially 13.56 MHz. Additional electrode plates 940 are included in adjacent locations within the substrate 110 and form a capacitor C4 with the electrode plane 930. Switches 240 associated with the keys of the keyboard selectively connect the RFID integrated circuit 220 to the additional electrode plate 940 for activating the RFID integrated circuit 220 in operation.

FIG. 17b is a circuit implementation illustration of the keyboard when implemented according to FIG. 17 a. The resonant circuit formed by the capacitors C2 and C3 in combination with the inductor L is operable to amplify the signal formed across the capacitor C2 by a factor of Q of the resonant circuit through resonance at 13.56 MHz. When the keyboard is implemented electrostatically as described, the signal developed across the inductor L is selectively coupled to their respective RFID integrated circuits 220 through the capacitor C4 in response to depressing a key of the keyboard; the integrated circuit 220 is thus activated and operable to communicate back through the capacitors C4, C3 and C1 to the mobile phone 10 or similar device placed on the aforementioned floating conductive plane 910, which floating conductive plane 910 constitutes one plate of the capacitor C2.

In the foregoing, the operation of the keyboard according to the present invention by magnetic coupling and also by electrostatic coupling has been described. It should be understood that embodiments of keyboards in accordance with the invention can be implemented using a combination of magnetic and electrostatic coupling techniques; for example, in one embodiment, the keypad 100 may be implemented using magnetic coupling from the mobile phone 10 or similar device to the resonant circuit implemented by the inductor 140 and the capacitor 150, followed by electrostatic coupling from the resonant circuit to the RFID integrated circuit 220 by switching. Other combinations of coupling techniques are also possible when implementing embodiments of the keyboard according to the invention.

When using electrostatic coupling, i.e. capacitive coupling, as shown in fig. 17a and 17b, the switches 240 associated with the keys of the keyboard can be implemented to be capacitive, thereby improving the reliability of the keyboard by circumventing the need to make electrical contact in operation. When adjacent conductors are moved closer together, the capacitive coupling therebetween may increase. Thus, in the implementation of the keyboard shown in fig. 17a and 17b, the capacitive coupling switches used with the keys are generally indicated by 1000 in fig. 18. The capacitive coupling switch 1000 includes a first electrode plate 1010 embedded in or on the substrate 110 of the keypad, and a second electrode plate 1020 inside the keys of the keypad. The key is made of a highly elastic material, such as soft silicone rubber. Alternatively, the elastomeric material may comprise one or more cavities, i.e. one or more voids. In operation, a force applied by a user to the exposed upper surface of the key causes the key to elastically deform towards the substrate, thereby bringing the electrode plates 1010, 1020 closer to each other and thus increasing the capacitance therebetween for coupling a further 13.56MHz signal therebetween.

While the operation of the embodiments of the present invention have been described above as using signals having a frequency of primarily 13.56MHz, it will be appreciated that embodiments of the present invention are readily modified to operate at frequencies other than 13.56 MHz.

With reference to the mobile phone 10 shown in fig. 1 and 2, a software product may be downloaded into the memory of the data processor 60 to enable the phone 10 to operate with the various embodiments of the keypad according to the invention described above. Execution of the software product causes the data processor 60 to activate the wireless interface 90 to emit interrogating radiation, for example at a frequency of 13.56 MHz. When the telephone 10 is placed adjacent the aforementioned area 130 of the keypad 100, energy is selectively coupled to one or more RFID integrated circuits 220 of the keypad 100 in response to a user activating one or more keys of the keypad 100. The one or more selectively coupled RFID integrated circuits 220 are powered and then respond by outputting a signature encoded signal unique thereto. The signature encoded signal is transmitted back to the mobile telephone 10 via region 130 and is finally received at the data processor 60 for use therein. For example, when the keyboard includes a display 510 as depicted in fig. 12, the data processor 60 is optionally operable to display a symbol of the display screen 20 and/or output a signal to cause this symbol to be presented on the display 510 of the keyboard. The software product is preferably written in Java or Javascript, although other computer languages may be used; furthermore, the software product is advantageously loaded into the mobile phone 10 by means of a wireless carrier signal or by means of a physical data carrier, such as a miniature optical disc or a plug-in solid-state data storage. When the mobile telephone 10 is replaced by an alternative device, such as a Personal Digital Assistant (PDA) or similar device, appropriate modifications to similar considerations of the data product are required.

Modifications to the embodiments of the invention described in the foregoing are possible without departing from the scope of the invention, which is defined by the accompanying claims.

Referring to fig. 8 and 9, the key columns in the illustrated keyboards 100a, 100c are beneficial for improving energy coupling efficiency and facilitating manufacturing, in that a respective single inductor 210 is provided for each key for their respective RFID integrated circuits 220, rather than providing each RFID integrated circuit 220 individually with a respective associated inductor 210. This benefit results from the more favorable coupling obtained by the inductor 210 being placed around the inside of the additional area 160 rather than adjacent to the periphery of the additional area 160. Thus, the implementation of the keyboards 100a, 100c shown in fig. 8 and 9 is particularly advantageous in operation.

It is intended that expressions such as "comprising," "including," "containing," "incorporating," "being," "having," and the like be interpreted in a non-exclusive manner, i.e., that there be other items or components that are not expressly defined. Reference to the singular should also be construed to relate to the plural.

Numerals included within parentheses in the accompanying claims are intended to assist understanding of claimed subject matter and are not intended to determine the scope of the claims.

Claims (12)

1. A keyboard (100) comprising a plurality of user-operable alphanumeric keys (240), the keyboard (100) comprising one or more identification devices (220) associated with the user-operable alphanumeric keys (240), and wherein, in response to user actuation (250) of one or more of the user-operable alphanumeric keys (240), the one or more identification devices (220) are operable to selectively communicate with a numeric apparatus (10) positioned adjacent the keyboard (100),

the method is characterized in that:

(a) the keyboard (100) comprises a flexible substrate for enabling the keyboard to be folded and/or rolled into an inactive state of non-use and unfolded and/or unrolled into an active state of use in communication with the digital apparatus (10);

(b) the keyboard (100) is operable to communicate with the digital device (10) by near field magnetic and/or electrostatic coupling when in proximity to the digital device (10);

(c) the keyboard (100) comprises an intermediate resonant circuit for interfacing between the one or more identification devices (220) and/or display drivers (510) and the digital apparatus (10), wherein the intermediate resonant circuit is operable to exhibit a Q factor greater than 1 for providing signal enhancement to enable the one or more identification devices (220) to derive energy from power delivered thereto by the intermediate resonant circuit; and

(d) the keyboard (100) further comprises a pixel display (510) with an associated display driver (510) for receiving, in operation, data from the digital device (10) via an intermediate resonant circuit that, in operation, presents visual information to a user of the keyboard (100).

2. The keyboard (100) of claim 1, wherein the pixel display (510) is implemented with an organic printable electronic element operable to bend when the keyboard (100) is operated between its inactive folded state and its active unfolded state of the keyboard (100).

3. The keyboard (100) of claim 1, wherein the Q factor is in the range of 10 to 100.

4. The keyboard (100) of claim 1, wherein the intermediate resonant circuit is only coupled for communicating alternating signals induced therein to the one or more identification devices (220) and the digital apparatus (10).

5. The keyboard (100) of claim 1, wherein the substrate comprises a plurality of layers bonded, laminated, and/or molded together.

6. The keyboard (100) of claim 5, wherein the plurality of layers are bonded, laminated and/or molded together in roll form during manufacture of the keyboard.

7. The keyboard (100) of claim 5, wherein the plurality of layers comprises at least one of: polymeric insulating layer, conductive layer, printed electronic polymeric layer, surface mount electronic chip component layer, surface mount passive component layer.

8. A keyboard (100) as claimed in claim 1, wherein the intermediate resonant circuit is operable to exhibit a resonant frequency of substantially 13.56 MHz.

9. The keyboard (100) of claim 1, wherein at least one of the one or more identification devices (220) is operable to multiplex a plurality of keys (240) of the keyboard (100) for monitoring user actuation of the keyboard (100) during operation of the keyboard (100).

10. The keyboard (100) of any one of the preceding claims, the keyboard (100) having its keys (240) selectively spatially arranged to assist with one or more of: -entering alphanumeric data into the digital device (10), -playing a game executed in the course of communicating with the digital device (10).

11. The keyboard (100) of claim 1, wherein the keyboard (100) includes a power source (300) therein, the power source (300) being operatively coupled to provide energy to the one or more identification devices (220) if insufficient power is available to be coupled from the digital apparatus (10) through the intermediate resonant circuit to provide energy to the one or more identification devices (220).

12. A method of using a keypad (100) including a plurality of user-operable alphanumeric keys (240), wherein the keypad (100) includes:

one or more identification devices (220) associated with the user-operable alphanumeric keys (240), and wherein the one or more identification devices (220) are operable to selectively communicate with a digital apparatus (10) positioned adjacent the keyboard (100) in response to user actuation (250) of the one or more user-operable alphanumeric keys (240);

an intermediate resonant circuit operable to exhibit a Q-factor greater than 1 for providing signal enhancement to enable the one or more identification devices (220) to derive energy from power delivered to it by the intermediate resonant circuit;

a pixel display (510) having an associated display driver for receiving, in operation, data from the digital device (10) via an intermediate resonant circuit that, in operation, presents visual information to a user of the keyboard (100); and

a flexible substrate;

characterized in that the method comprises:

(a) causing the keyboard to be folded and/or rolled into an inactive state of non-use, or to be unfolded and/or unrolled into an active state of use in communication with the digital apparatus (10);

(b) utilizing the keyboard (100) to communicate with the digital device (10) through near field magnetic and/or electrostatic coupling when in proximity to the digital device (10);

(c) interfacing between the one or more identification devices (220) and/or display drivers (510) and the digital apparatus (10) using an intermediate resonant circuit in the keyboard (100);

and

(d) data is received that when operated presents visual information to a user of the keyboard (100).