HK1101210A - Input devices and their use - Google Patents

Description

Input device and application thereof

The application is a divisional application of an invention patent application which is submitted at 22/5/2001, has an international application number of PCT/US01/16461, enters the Chinese national stage at 26/12/2002, has a national application number of 01811773.2 and is named as an input device and application thereof.

Technical Field

The present invention relates generally to devices for inputting data to electronic devices, such as touch pads, keypads, and voice recognition systems, and more particularly to keypads that output keys determined by individual switch activations and adjacent switch combination activations.

Background

Miniaturization of electronic products is a major principle of process development. A successful production line with competitive advantages depends in large part on the ability of companies to successfully provide ever-increasing functionality and more portable products. As technology advances, circuit size can be made smaller under manual scale, resulting in interfaces (e.g., screens, keypads, cursor control devices) becoming a limiting factor for portable products. Thus, as portable products enter the field, the quality of ergonomics and the size of their input devices (e.g., keypads) have an increasingly important impact on the acceptance and success of the products. Of particular significance is the telephone keypad, which is of importance as a basic, economical communication tool worldwide. For example, international standards have been established for the minimum dimension between adjacent key switches in order to accommodate the fingertips of the average person. A "key" refers to an element in an array of elements on a surface that, when struck, produces an identification output signal corresponding to the position of the element. By way of example, the term "keypad" includes a localized area on a touch screen having a similar behavior as a key, as well as a localized area on a keypad formed by placing a layer of film over an array of touch switches. "keypad" means an array of keys or keypads, including conventional keypads (e.g., found in most telephones, calculators, etc.), keyboards, and similar touch sensitive devices implemented with touchscreens or demarcated zones on the surface of a film. Such surfaces are generally planar, but may also be curved.

Some of the early efforts of the pen workers have been directed to reducing the size of keypads by developing keypads in which the output keys are determined by a single switch activation and a combination of adjacent switches activation. Some of the earlier work is disclosed in my U.S. Pat. Nos. 5,612,690 and 5,973,621, the entire contents of which are hereby incorporated by reference. Such keypads are referred to herein as "IACK" keypads, or independent-combination key keypads.

In the context of this document, an "independent key" or "independent keypad" is a raised area on the surface of a keypad having individual graphical elements (graphical elements) that, when pressed individually, produce a corresponding output. On the other hand, a "combination key" or "combination keypad" is a partially depressed area on the surface of an "IACK" keypad that produces a unique output, typically corresponding to a central graphical element, as a result of simultaneous or nearly simultaneous operation on a set of two or more adjacent (e.g., diagonally adjacent or "kitty corner") independent keypads. The term "defined combination" refers to any combination of individual keys corresponding to a combination key, as interpreted by the associated device. Conversely, an "undefined combination" means that when a group of independent keys is pressed simultaneously, there is no corresponding defined combination key.

Thus, an IACK keypad is a keypad that includes individual and combination keys or keypads. Such keypads feature, for example, individual key regions identified by graphical elements on a surface that is slightly raised relative to an adjacent surface on which other graphical elements are located to identify combination key regions. It is possible to design a keypad having the advantage that the spacing between adjacent independent key intervals is very small.

It is desirable to improve the accuracy of IACK keypads and other input devices in interpreting user intent, regardless of the switch technology used. In implementations where strong tactile feedback is required, such as with metal domes, there is a particular need to determine whether the user's intent is a single or combined key output on an IACK keypad. There is also a need for an improved ergonomics of such keyboards and better algorithms that can easily interpret input, such as in the case of telephones and the like.

Other improvements in the design and implementation of keypads or other input devices are desired.

Disclosure of Invention

The present invention features improved IACK keypad and other data entry device apparatus, and their integration with electronic devices.

In accordance with one aspect of the present invention, a telephone having an IACK keypad with a combination keypad and independent keypads defined by alternating columns, the keypad having a combination keypad column including a plurality of columns of numbers including numeric areas corresponding to the numbers 0 through 9, each of the columns of numbers including a plurality of numeric areas, and at least one other column including a keypad corresponding to a punctuation mark.

Preferably the telephone has three columns of numbers such that the columns of numbers together form a standard telephone key layout, the column of numbers on the left comprising 1, 4, 7, the column of numbers in the middle comprising 2, 5,8, 0 and the column of numbers on the right comprising 3,6, 9.

In some embodiments, the keypad is defined by a corresponding perceptible feature on an exposed surface formed by the flexible membrane. By "perceptible" is meant the ability of a person to sense by its senses. For example, the perceptible component may include a protrusion variation across the surface of the film (e.g., with tactile perception). In other cases, the perceptible element may be a simple visual distinction. Preferably, the numeric keypad is significantly larger than the keypad corresponding to the punctuation mark.

In some embodiments, the independent keypad and the combination keypad are different sizes.

In some applications, the independent keypads collectively include keypads corresponding to letters of the alphabet (e.g., letters A through Z of the English alphabet).

In a particular compact keypad layout, the individual key regions are preferably spaced apart with a pitch no greater than half the width of a human fingertip, and in some cases each key region carries an associated, visible graphical symbol. The combination keypads may also be arranged in columns of different widths.

In some arrangements, the numeric columns are distinctly different in coloration from the column or columns containing the primary punctuation marks, and the coloration of the columns may alternate, e.g., dark-light-dark.

In a preferred embodiment, the independent key regions are arranged in six vertical columns defined by the positioning of the key icons, the independent key regions are arranged in first, third, fifth, seventh, ninth and eleventh vertical columns including regions corresponding to letters, the number of columns forming the combination numeric keypad are the second, sixth and tenth vertical columns, and the fourth and eighth vertical columns include key regions corresponding to punctuation marks. The number of columns may be counted from either side of the keypad.

In the construction of the phone, when a key region corresponding to a punctuation mark is consecutively operated twice, different punctuation marks, preferably two or more related marks, can be represented. For example, pressing the colon key twice represents a double quotation mark (semi-colon), pressing the period key twice represents a comma, and so on.

In accordance with another aspect of the present invention, an IACK keypad is covered with an exposed surface that defines combination key regions and independent key regions in alternating columns, the independent key regions being formed with raised dots that are higher than the combination key regions. The exposed surface forms a continuous, smooth contour between adjacent independent key regions, and the common boundary between adjacent independent key spaces in the underlying key spaces is free of indicia. By "continuous, smooth outline" is meant that there is no common boundary marking of individual keys that can be tactilely sensed on the surface between the raised points, such as at the edges of individual active keys. Such a continuous, smooth contour may (and in some cases is preferred) be provided with visible icons corresponding to combination keypads associated with the smooth surface.

In some preferred embodiments, the bumps are diamond shaped with the ends or endpoints pointing to adjacent combination key regions.

In accordance with another aspect of the present invention, an IACK keypad defines combination key regions and independent key regions in alternating columns, the standard orientation being defined by icons associated with the independent and combination key regions, the alternating columns being arranged along a line inclined at an angle (e.g., a 45 degree angle) according to the standard orientation of the keypad.

According to another aspect of the invention, a keypad for a telephone includes keypads arranged in columns, including two columns of numbers, a majority of the keypads in the columns of numbers corresponding to a selection of a number from a list consisting of 0 through 9, and at least one punctuation column, a majority of the keypads in the columns of punctuation corresponding to punctuation marks.

In accordance with another aspect of the present invention, an IACK keypad is covered with an exposed surface that defines combination key regions and independent key regions in alternating columns and alternating rows. The exposed surface forms a continuous, smooth contour between adjacent individual key regions, with no visible features marking the boundaries between adjacent key regions in a direction parallel to the columns or rows.

According to another aspect of the invention, the keypad has first and second sets of keys arranged thereon. The first set of keys are arranged in a first plurality of rows, each row having a second plurality of members, each member being a contact region having a first shape and a first area, the first shape and the first area being at least as large as a size of a tip of a human finger. The first set of keys also defines interstitial regions not occupied by members of the first set, and the elements of the second set of keys are within the interstitial regions, having a second shape and a second area (e.g., diamond shape), the second area being substantially smaller than the first area.

In some preferred embodiments, the contact area of each key in the first set is located on a first horizontal plane, the contact area of each key in the second set is located on a second horizontal plane, and the second horizontal plane is positioned above the first horizontal plane.

In some applications, the keypad is an IACK keypad, wherein each member of the first set of keys is a combination key and each member of the second set of keys is an independent key.

In some embodiments, the keypad further includes a non-linear tactile feedback system coupled to the key arrangement to provide each key with tactile feedback approximately proportional to the contact area of the key.

In accordance with another aspect of the present invention, an IACK keypad is covered with an exposed surface on which a key matrix of alternating columns and alternating rows define combination key regions and independent key regions. Between the fourth and fifth rows of combination key regions, tactile bumps are placed on the outside of the key matrix to distinguish the boundaries of the telephone keypad, which includes the combination key regions from the first to fourth rows of the matrix.

In accordance with one aspect of the present invention, the "interstitial" nature of the combination keys is preserved by the user by eliminating the visible panes associated with the individual keys in prior art IACK keypads. Unlike prior art IACK keypads in which the combination keys are implemented with elements placed at the intersections of the edges of the individual keys, the present invention implements the individual keys with a (larger) void area of the combination keys. According to another aspect of the invention, the IACK keypad layout of the phone provides a higher degree of third functionality (e.g., punctuation) by alternating columns and columns between symbol categories, such as numbers, punctuation, numerals, punctuation, numbers. This aspect can be further improved by varying the width and/or color of adjacent rows. According to one aspect of the invention, the structure of the IACK keypad is rotated 45 degrees, resulting in a reduced width IACK keypad. This configuration may enable a standard "QWERTY" layout to achieve a high ergonomic comfort level within a narrow width (e.g., within as little as 58 millimeters).

In accordance with another aspect of the invention, a touch sensitive input device (e.g., a small push pad or touch pad) has an exposed, continuous surface defining a flat area, and a grid of sensing elements coextensive with the area of the exposed surface and capable of determining the noted prominent position in the exposed surface by an operator in response to contact with the exposed surface. The exposed surface may be varied in height across the flat area to form a series of haptic elements.

In some embodiments, the haptic elements are comprised of raised dots. Preferably, the bump expands at least about 0.75 millimeters relative to the adjacent area of the exposed surface. In some examples, the exposed surface of the device carries an icon associated with the haptic element. For some applications, the haptic elements may each define an area on the surface corresponding to an associated alphanumeric symbol.

In some cases, the input device is configured to output a sequence of alphanumeric characters when the corresponding contact members on the surface are successively activated, for example with a keypad. In certain preferred embodiments, the device is an IACK keypad and the haptic elements are comprised of raised dots that define individual key regions on the IACK keypad. The preferred embodiment further includes circuitry adapted to temporarily display alphanumeric characters on the screen as the operator traverses the exposed surface, with the alphanumeric characters displayed selected by the operator to correspond to the location of contact on the exposed surface.

In accordance with another aspect of the present invention, an electronic device including an IACK keypad has an exposed, continuous surface defining independent key regions and combination key regions; a grid of sensitive elements beneath the surface of the keypad responsive to the position of human fingers on the surface of the keypad; there is also a circuit adapted to receive a signal from the IACK keypad indicative of the state of the keypad and to generate an output responsive to the keypad activity of the operator. The circuitry is configured to determine the intended combination key based at least in part on the sensed position of the finger between the centers of adjacent independent key regions.

In some embodiments, the device further includes a keyswitch matrix responsive to depression of the independent keypad, the circuitry being configured to determine the intended combination key based on the sensed finger position and a state of the keyswitch matrix. In some cases, the grid of sensing elements shares some conductive traces on a printed circuit board with the keyswitch matrix.

The grid spacing of the grid of sensitive elements may be larger than the spacing of the centers of adjacent independent key regions, which still provides an acceptable resolution.

In accordance with another aspect of the invention, an electronic device has a substrate with a first array of spaced-apart, electrically conductive trace elements thereon; and a flexible cover layer disposed over the base layer and having a second array of spaced apart, electrically conductive trace elements. The first and second arrays together form a coordinated system, with the cover layer being separated from the base layer by an array of resilient, movable (collapsible) elements and having an exposed, continuous surface. The first and second arrays of trace elements also form a capacitive grid responsive to operator manipulation (digit) on the surface of the overlay. A circuit is adapted to sense a capacitive state of the grid and determine the position of the finger based on the sensed capacitive state.

In certain preferred embodiments, the continuous surface defines key regions of a keypad, and the circuitry interprets desired keypad input based at least in part on the sensed capacitive state of the grid.

In some cases, the capacitive grid is responsive to localized deflection of the cover layer toward the underlayer, with the active elements being integrally stamped to extend from a surface of the cover layer opposite the underlayer.

In one example of implementation, the device takes the form of an IACK keypad having an exposed surface defining independent key regions and combination key regions.

According to another aspect of the invention, a keypad comprises: an outer cover layer having an exposed, continuous surface defining a keypad; a grid of sensitive elements beneath the surface of the overlay responsive to the position of a human finger on the surface of the keypad; and a single switch adapted to change state when any of the multiple functions of the keypad is depressed (preferably, any keypad of the keypad is depressed)

In some embodiments, the keypad is an IACK keypad having a bare, continuous outer surface defining independent key regions and combination key regions; and a separate switch adapted to change state when any of the independent keypads is pressed. The independent keypad may protrude above the combination keypad.

According to one aspect of the invention, an input device has an overlay with an exposed surface defining regions associated with respective discrete inputs; and a bottom layer below the surface. The cover layer has a variable capacitive grid and the base layer has another, preferably vertical, grid array. The apparatus further has a circuit adapted to account for large capacitance changes in the grid when the overlay layer has a local offset toward the underlay at a location identified by the capacitance change; and accounting for small changes in capacitance of the grid when generating the direction and extent of the finger's motion along the surface.

According to one aspect of the invention, a measuring device is integrated within an IACK keypad at a distance. In one embodiment thereof, the measuring device is used to improve the reliability and accuracy of an IACK keypad. By identifying the position of the finger in addition to or independently of the associated switch matrix, errors resulting from ambiguity of the subset of switches within the combination key can be eliminated. In another embodiment, the measurement device is placed under an IACK keypad, providing a "mouse" function. In certain preferred embodiments, the number of wires of the integrated system is the same as the number of individual IACK devices. In one embodiment, two vertically oriented arrays are placed on different elements: one on the PCB and the other under the IACK element. In this embodiment, the finger is positioned using the change in parasitic capacitance (between array intersections) to achieve mouse and keypad functionality, however, the change in capacitance resulting from physical displacement of the IACK keypad is relatively large compared to the parasitic capacitance. Thus, the finger movement can be easily discerned with the activation of the keys despite the overlap of signals that may occur. In another embodiment, measuring means at a distance are integrated with the keypad matrix. In another embodiment, the tactile response is generated by a piezo-ceramic element (placed on a layer across the surface, or placed discretely). The tactile response may also be provided by the same element used to vibrate the device, since the positioning of a human finger is difficult to reach frequencies within this range.

Integrating the position measurement system with the IACK keypad may provide several advantages. For example, in mouse mode, the surface of the IACK keypad may provide stability for the fingers in motion. This is a serious problem because of the inherently constantly intermittent and unstable movements that occur in motion. Precise control of a cursor on a small handheld device (e.g., a telephone) is a frustrating task if the user is riding a bus, train, car or walking. This problem can be addressed by placing a protruding reference bump on the surface along the touchpad or other cursor control position measurement system by providing a reference point for the position of the finger. The raised reference bumps in some implementations may provide a tactile reference for the user, by providing a small protrusion, mechanically stabilizing the finger to better hold the hand in place. When the finger is between the convex points, the support is generated by the part surrounding the convex points, and when the finger is in the central position above the convex points, the convex points wrapped in the finger belly are captured by the flexibility of the finger. By thus stabilizing the finger, a high degree of accuracy may be provided in a motion environment that may otherwise be frustrating. The device may be configured to generate an audible cue (e.g., sounding a digitized letter or number) or a visual cue (e.g., changing the displayed characters, especially a large font that may fill a large portion of the screen) as the user moves a finger across the surface of the device. The implementation of sound is particularly useful for blind users, and the form of vision is particularly useful for people with weak eyesight. The invention provides the required consistency and efficiency for the user, and the functions of the mouse and the IACK small keyboard can be obtained without moving the palm.

In accordance with another aspect of the invention, an IACK keypad has a bottom layer with an array of sensitive elements arranged to change state in response to keypad operation; a flexible (i.e., resilient) cover layer disposed over the base layer having an exposed surface defining an array of independent key regions and combination key regions defined in spaces between adjacent independent key regions; and an array of discrete contact elements extending between and separating the cover layer from the base layer. Each contact element is located between two adjacent independent key regions and is adapted to generate a resilient compression as a non-linear response to localized pressure on the exposed cover surface to generate tactile feedback of keypad operation.

In some cases, the contact elements are placed below the combination keypad. In some cases, the contact elements are placed between immediately adjacent independent keypads. By "directly adjacent" is meant that no combination key regions are directly defined between the independent key regions, e.g., adjacent independent keys in adjacent columns in an alternating matrix. In some cases, the contact elements include contact elements that are positioned below the combination keypads, and contact elements that are positioned directly between adjacent independent keypads in between.

In some embodiments, four corresponding, spaced apart contact elements are disposed about the periphery of each individual keypad and each combination keypad, with the gap between four adjacent contact elements corresponding to one keypad. Each contact element is preferably positioned equidistant between the centers of adjacent independent keypads and equidistant between the centers of adjacent combination keypads.

In some embodiments, each of the independent key regions defines an exposed pressure contact area, and the keypad further includes an array of conductive balls (conductive balls) between the bottom layer and the cover layer. Each conductive pellet is centered under a corresponding independent keypad and extends sideways (e.g., toward an adjacent combination keypad) beyond the pressure contact area of the independent keypad with which it is associated. By "contact area" is meant the area of the independent keypad that acts as a button during operation, transmitting the pressure of the operator's finger, causing the keypad overlay to flex. Such areas do not include those areas that are subject to incidental, non-loaded contact with the operator's finger. Thus, during operation of a single independent keypad, substantially all (e.g., ninety percent) of the load applied by the operator is applied to the pressure contact area.

Some embodiments include an array of discrete contact elements extending between and separating the cover layer from the base layer. Each contact element is disposed between two adjacent independent key regions, and the elastic compression generates elastic feedback to the operation of the keyboard as a non-linear response to local pressure on the outer surface of the exposed cover layer.

In some cases, the independent key regions include raised bumps whose upper surface end boundaries limit their pressure contact area, or diamond shaped bumps, with a shelf oriented between adjacent combination key regions.

In some configurations, there are three contact elements between each adjacent pair of independent key regions, distributed along a line segment in the middle of the pair of independent key regions (e.g., along a boundary separating the two independent key regions). Preferably, the three contact elements are evenly distributed along the line segment, one directly between the centers of a pair of independent key regions and one in the space between four adjacent independent key regions at one end of the line segment.

In certain particularly preferred embodiments, the contact elements are formed by integrally molding an elastomeric material (e.g., silicone) with and extending over the rear surface of the cover layer.

In some examples, the contact element is in the form of a cell (Clusonical).

Preferably, the contact elements are optimally arranged: in response to pressing the independent keypad and the combination keypad, nearly equal tactile feedback is generated. Also preferably, the contact elements are constructed and arranged: almost the same vertical activation pressure is required for both the independent keypad and the combination keypad.

In accordance with another aspect of the invention, an IACK keypad has a bottom layer with an array of sensitive elements arranged to change state in response to keypad operation; a flexible (e.g., elastomeric) cover layer disposed over the base layer having an exposed surface defining an array of independent key regions and combination key regions defined in spaces between adjacent independent key regions; and an array of discrete contact elements extending between and separating the cover layer from the base layer. Each contact element is located between two adjacent independent key regions and is adapted to generate a resilient compression towards the bottom layer as a non-linear response to local pressure on the exposed cover surface to generate tactile feedback of the operation of the keypad. Each contact element has a profile that is symmetrical about an associated axis that is perpendicular to the base layer and intersects the cover layer between adjacent independent key regions.

Preferably, the contact elements have a cell-like shape, or a shape that can provide the same function, like a hollow, volcano-like shape, producing nearly the same non-linear bending response.

In some cases, the contact elements are integrally molded with the cover layer from a resilient material and extend from a rear surface of the cover layer.

In some embodiments, there are at least four corresponding contact elements in each independent keypad grid space, spaced apart around the independent keypad, with each gap between four adjacent contact elements corresponding to a keypad. Preferably, the contact elements are arranged as: in response to pressing the independent keypad and the combination keypad, nearly equal tactile feedback is generated.

In accordance with another aspect of the invention, an IACK keypad has a substantially planar bottom layer with an array of sensitive elements arranged to change state in response to keypad operation; a flexible cover layer disposed over the base layer has an exposed surface defining an array of individual key regions arranged in rows, with at least one continuous, elongated contact element extending from adjacent at least three of the key regions in a row of key regions, extending between the cover layer and the base layer and separating the cover layer from the base layer. The contact elements are adapted to generate a resilient compression as a non-linear response to local pressure on the exposed cover surface to generate tactile feedback of keypad operation.

In some configurations, a keypad has a plurality of such contact elements forming a rail extending between adjacent rows of keypads.

For example, the contact element may include a rib supported at an angle (e.g., 60 degrees) relative to the plane of the base layer configured to flex in response to localized pressure on the exposed cover layer surface.

In accordance with another aspect of the invention, an IACK keypad has a substantially planar bottom layer with an array of sensitive elements arranged to change state in response to keypad operation; a flexible cover layer disposed over the base layer has an exposed surface defining an array of independent key regions arranged in rows and columns defining combination key regions in spaces between adjacent independent key regions. The cover layer further includes a rear surface facing the base layer and separated from the base layer by flexible contact elements between the cover layer and the base layer, the rear surface having an array of conductive pellets disposed below locations corresponding to the independent key regions. Each conductive pellet extends through the rear surface of the bottom layer to one side of the center of one adjacent combination keypad by a distance of 50 to 70 percent (preferably, about 50 percent) of the distance between the center of the adjacent combination keypad and the center of the independent keypad corresponding to the pellet.

In some configurations, the conductive pellets have a cross shape with a shelf extending toward a plurality of adjacent combination key regions.

Preferably, the edge of each conductive pellet closest to the end of the adjacent combination keypad is perpendicular to a straight line connecting the center of the adjacent combination keypad and the center of the independent keypad corresponding to the pellet.

In some cases, the substrate includes a sloped outer region that extends away from the substrate, where the pellet includes a contact surface that faces the substrate.

In accordance with another aspect of the invention, an IACK keypad has a substantially planar bottom layer with an array of sensitive elements arranged to change state in response to keypad operation; a flexible cover layer disposed over the base layer. The overlay has an exposed surface defining an array of independent key regions arranged in rows and columns, the combination key regions defined in spaces between adjacent independent key regions; and a rear surface facing the substrate and separated from the substrate by a flexible contact element between the cover and substrate. The rear surface has an array of conductive pellets disposed beneath the locations corresponding to the independent key regions, each pellet including a contact surface facing the bottom layer, the bottom layer including a sloped outer region extending away from the bottom layer.

In certain preferred embodiments, the conductive pellets have a cross shape with a shelf extending toward a plurality of adjacent combination key regions, the shelf of the conductive pellets including a sloped outer region.

Preferably, each of the conductive pellets extends through the rear surface of the bottom layer to one side of the center of one of the adjacent combination key regions by a lateral distance of 40 to 99 percent (preferably, 50 to 99 percent, and more preferably, 70 to 80 percent) of the distance between the center of the adjacent combination key region and the center of the independent key region corresponding to the pellet.

In accordance with another aspect of the invention, an IACK keypad has a bottom layer with an array of sensitive elements arranged to change state in response to keypad operation; a flexible (e.g., elastomeric) cover layer disposed over the base layer and having an exposed surface defining an array of independent key regions and combination key regions defined in spaces between adjacent independent key regions; and an array of discrete contact elements extending between and separating the cover layer from the base layer. Each contact element is located between two adjacent independent key regions and is adapted to generate a resilient compression towards the bottom layer as a non-linear response to a local pressure on the exposed cover layer surface, generating a tactile feedback of the operation of the keypad, and the contact elements are arranged: in response to pressing the independent keypad and the combination keypad, nearly equal tactile feedback is generated.

In accordance with another aspect of the invention, in a novel method of manufacture employing a matrix including tapered perforations, a cone of elastomeric material is cast underneath an IACK element. In accordance with another aspect of the invention, the tactile feedback element is placed at a midpoint between adjacent independent key regions, and may be formed from a cone of elastomeric material molded underneath the IACK element. In accordance with another aspect of the present invention, the tactile feedback element of an IACK keypad is realized by a metal element, embossed on an arcuate element placed at a midpoint between adjacent independent key regions.

According to another aspect of the invention, a method of interpreting IACK keypad input is presented. The method comprises the following steps: the method includes sensing keypad input corresponding to combined actuation of a plurality of independent keypads on the keypad and comparing the sensed input to a predefined sequence of independent key inputs corresponding to the combined keypads. If the sensed input is found to correspond to multiple independent key regions associated with the combination keys, a combination key input is registered. If the input is found not to coincide with any of the combination keys, the sensed input is compared to the customized key association. If the sensed input is found to correspond to a customized key association, a character sequence is registered based on the corresponding key association.

In some implementations, if the sensed input is found not to correspond to any combination key or any recorded custom key association, a character sequence is generated that is determined solely by the plurality of independent key regions of the sensed input. In some cases, the character sequence is generated by arranging the input independent keypads according to a predetermined order.

In some applications, if the sensed input is found not to correspond to any combination key or any recorded custom key association, the association between the sensed input and the selected string is stored in a readable memory. As an example, a character displayed on the display screen while sensitive to input may define a selected string of characters.

In some embodiments, if the sensed input is found not to correspond to any combination keys, the method comprises: comparing the sensed input with a last registered input character prior to the sensed input to determine whether the last registered character is among the plurality of independent key regions of the sensed input, and deleting the last registered character if the last registered character is found to be among the plurality of independent key regions of the sensed input.

According to another aspect of the invention, as a method for a user to simultaneously enter a designated sequence of digits, such as a Personal Identification Number (PIN), or an access code (such as a telephone number followed by a PIN code), the electronics of an IACK keypad and accompanying algorithm enable the entry of multiple keys to be registered simultaneously. According to another aspect of the invention, an algorithm is provided for mapping from alphabetic keys to numeric outputs, such as the correlations displayed by a standard 12-key telephone keypad.

In certain aspects, the present invention takes advantage of the ability of the IACK keypads disclosed above to simultaneously detect the entry of any independent keypad or even a combination of non-adjacent keypads. This method has the advantage of providing a secure and fast method for entering a digital code, which can be used, for example, in: providing access to web sites and other telephony services and content; entering its phone number before the PIN to access the voicemail; and so on.

In accordance with another aspect of the invention, the telephone has a keypad defining an alphanumeric keypad corresponding to individual letters, a numeric keypad corresponding to individual numbers, and a circuit coupled to the keypad for receiving input generated upon user activation of the various keypads. The circuitry is configured to: alphabetic input is translated to numeric output in the form of numbers 2 to 9 according to the alpha-numeric correspondence of a standard telephone keypad. By "telephone" is meant in a sense that there is a means for receiving an operator input and generating a corresponding identifiable code, such as a code representing a telephone number associated with the input. For example, a stand-alone device that generates a telephone number but does not access the network (e.g., via voice conversion). In the narrower sense, means a device that accesses (either wired or wireless) a telephone network and communicates over the network.

In some embodiments, the circuitry is configured to: in the first mode, individual letters are displayed in response to activation of a selected letter key, and in the second mode, one of the numbers 2 through 9 is displayed in response to activation of a selected letter key, with the displayed number being selected according to the letter-to-number correspondence of a standard telephone keypad.

In some applications, the circuitry is configured to: when the associated letter key is activated, a letter sequence is registered, and in response to additional input from the operator, the registered letter sequence is converted to a telephone number according to the letter-to-number correspondence of a standard telephone keypad. In some instances, the circuitry is further configured to initiate a telephone conversation with the telephone number in response to the additional input.

Preferably, the circuit is adapted to register the numeric output according to the numbers associated with the numeric keypad so that the numeric input is not affected by the transformation.

According to another aspect of the invention, a method of telephone dialing is provided. The method comprises the following steps: a desired sequence of alphanumeric characters including at least one alphabetic character is input. The corresponding digit sequence is generated by converting alphabetic characters to one of the digits 2 through 9 according to the alpha-numeric correspondence of a standard telephone keypad.

In some cases, the method further comprises: after entering the letter sequence, the phone is notified to generate a corresponding number sequence.

For example, in many embodiments useful in english speaking countries, the desired alphabetic character sequence entered on the keypad includes at least 24 separate key regions, each corresponding to a different letter.

In some embodiments, the desired alphabetic character sequence is presented in vocalized form and entered vocalized. For example, a sequence of alphanumeric characters may include a series of alphabetic characters spelling out an audible word, such as "1-800-FLOWERS". These embodiments are preferably implemented using speech recognition algorithms that distinguish vocalizable words (e.g., "one, eight hundred") representing digits from non-vocalizable words (e.g., "flowers") and that only transform non-numeric words, particularly when the words that recognize digits are interpreted as digits to produce telephone numbers of reasonable length and format.

According to the present invention, there is provided a telephone with an IACK keypad comprising a combination keypad 3 and an independent keypad 2 arranged in alternating columns, wherein the columns of the combination keypad 3 comprise: three columns of numbers 70 and 72 comprising number areas corresponding to the numbers 0 to 9, each column of numbers comprising a plurality of said number areas, wherein the columns of said combination keypad 3 further comprise at least one further column 74 comprising keypads corresponding to punctuation marks, and wherein each two columns of numbers are separated from each other by one column 74 comprising keypads corresponding to punctuation marks, and wherein said independent keypads 2 comprise areas corresponding to letters of the alphabet.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

Drawings

Fig. 1 and 2 are cross-sectional views of two keypad embodiments integrated with a position measurement system.

Fig. 3 is a plan view of an integrated position measurement grid and keyswitch matrix, depicting four different types of keyswitch grids.

Fig. 4 shows a keypad with a doped overlay layer rather than bare pellets.

Fig. 5 shows a keypad without a conventional keyswitch matrix but with a position measurement grid.

Figure 6 shows a keypad with a position measurement grid having a set of trace elements on the lower surface of a flexible cover layer and a set of traces orthogonal to it on a bottom layer.

Figure 7A shows a keypad having contact elements formed from an array of piezoelectric devices of the high-up type. Figure 7B shows a keypad with a single piezoelectric element between the cover and base layers.

Figure 8 shows a keypad having a force sensitive resistor between the overlay and the substrate.

Figure 9 shows a keypad bottom layer that provides contact for all the switches in the matrix with a pair of separate electrical traces.

FIG. 10 shows the underside of the overlay layer of an IACK keypad having a first arrangement of conductive pellets. Fig. 11 shows a cross-sectional view along line 11-11 of fig. 10.

FIG. 12 shows the underside of the overlay layer of an IACK keypad having a second arrangement of conductive pellets. Fig. 13 shows a cross-sectional view along line 13-13 of fig. 12.

Fig. 14 is a side view of a solid layer formed with a material into which conductive pellets are pressed.

Fig. 15 shows a switched mesh pad structure for use with the overlay of fig. 12.

FIG. 16 shows the underside of the overlay layer of an IACK keypad having a third arrangement of conductive pellets. Fig. 17 shows a cross-sectional view along line 17-17 of fig. 16.

FIG. 18 shows the underside of the overlay layer of an IACK keypad having a fourth arrangement of conductive pellets. Fig. 19 shows a cross-sectional view along line 19-19 of fig. 18.

Fig. 20A and 20B illustrate deflection of the keypad overlay of fig. 17 and 19, respectively.

FIG. 21 is a partial perspective view of the underside of an IACK keypad overlay.

Figure 22 shows a keypad with a ball placed directly under the independent keypad.

Fig. 23 is a schematic diagram representing a telephone circuit.

Fig. 24 is a cross-sectional view of a two-part mold casting the lower surface of the keypad of fig. 22.

FIG. 25 is a perspective view of a first tactile feedback layer used under a keypad overlay.

FIG. 26 shows a keypad with a second tactile feedback layer. Fig. 27 is a front view of the feedback layer shown in fig. 26.

FIG. 28 is a perspective view of the smooth contour of the IACK keypad surface.

Fig. 29 and 30 are perspective and front views, respectively, of another IACK keypad face.

Figure 31 shows a preferred layout for an alphanumeric IACK keypad on a telephone.

Fig. 32 and 33 are cross-sectional views taken along lines 32-32 and 33-33, respectively, of fig. 31.

Fig. 34 is a layout of a QWERTY keypad with individual key columns arranged in diagonal lines.

FIG. 35 illustrates an algorithm for storing and identifying composition inputs.

FIG. 36 shows an inverse mapping algorithm for alphanumeric data to produce a digital output.

Figure 37 shows a standard telephone keypad alpha-numeric correspondence.

FIG. 38 is a perspective view of a third tactile feedback layer used under a keypad overlay.

Fig. 39 shows a keypad having a tactile feedback layer molded with an array of tapered contact elements.

FIG. 40 shows a scanning algorithm for an IACK keypad.

Fig. 41 shows a printed circuit board with traces extending at a 45 degree angle relative to the keyswitch matrix.

FIG. 42 shows an arcuate arrangement of the centers of the independent keypads added to the linear switch grid matrix.

Fig. 43 and 44 show front and perspective views, respectively, of a mobile phone having an IACK keypad.

In different figures, like reference numerals designate identical elements.

Detailed Description

Referring first to fig. 1, a flexible membrane 10 of a keypad element extends over a printed circuit board 12 on which is located a conventional keyswitch matrix 5 and a spaced apart position measurement system 20. The keyswitch matrix 5 is placed on the upper surface of the PCB 12 with the intersections of the traces forming switch grid pads 18 in a direction perpendicular to the conductive traces, making brief conduction by contact with conductive pellets carried on the lower surface of the membrane 10 directly above the corresponding pads 18. The membrane 10 has an undulating upper surface forming raised independent key regions 2 separated by valleys corresponding to the combination keys. The conductive pellets 16 may be formed of a solid material such as carbon impregnated with a conductive material or formed of an insulating material (e.g., the material forming the membrane 10) with a conductive ink or jacket. In this embodiment, the measurement system 20 includes two mutually overlapping arrays of linear elements (represented here by mutually perpendicular planar arrays 22 and 24), each of which serves as a printed layer of the printed circuit board 12. By way of example, such measuring devices are used in touch pads and other two-dimensional position responsive computer input devices. As illustrated by the grid space, the application of the measurement system 20 improves the accuracy of IACK keypads by helping to interpret ambiguous keypad operations as deterministic desired independent and combined keypad inputs. For example, in a keypad where the combination keys correspond to four independent keys activated simultaneously, imprecise finger positions typically only activate two adjacent keys (particularly in embodiments using discrete key switch technology), thereby causing ambiguity. In a keypad where a combination key corresponds to two independent keys activated simultaneously, inaccurate finger position typically activates only one of the two independent keys, resulting in erroneous independent key output. For example, combination keys may be placed at the edge of an IACK keypad or away from the edge, and when two adjacent such independent keys in a key column along the edge are activated together, an associated input may be generated, although in some cases a higher error rate may result. However, by independently determining the position of the finger with the position measurement system 20, it is possible to correctly address this accuracy issue and correctly interpret the desired input. For example, when it is desired to produce an output of 4 keys, the finger will be placed primarily over the associated void pattern corresponding to the combination key, however, due to the angle of the human finger, or physical irregularity of the user's finger, the pressure point may only include the lower two switch grid pads 18. In this case, ambiguities can be resolved with the position measurement system 20, even with only a relatively low resolution. A relatively inexpensive analog-to-digital converter can be used to provide a resolution equivalent to 1/4 finger width, or about 10 to 20 times lower resolution than typical commercial position measurement systems. Likewise, with this technique, in an IACK keypad, activation of a single key can be used to accurately interpret the user's intent, with the position measurement system 20 generating position information, and activation of any one of the key grid pads 18 will generate a "go/no go" message. This includes the unconventional keyswitch matrix 6, where a single contact is made anywhere across the keypad, as shown in FIG. 9.

The measurement system 20 also provides integrated "mouse" (icon control) functionality through the scanning of the individual PCBs 12 by the IACK keypad. In this embodiment, the position measurement system 20 operates in two modes. In the first mode, it provides positional location information about the finger position relative to the face of the IACK keypad to improve the accuracy of interpretation of IACK combination key operations, as discussed previously. In the second mode it is used to locate on-screen icons of products connected to the keypad. As an example, the user may effectively switch between the "mouse mode" and "keypad mode" keys by touching a button (not shown). The user can selectively turn off the combination key function or the independent key function of the IACK keypad, which has other advantages: for example, in a game application, the combination key may be set as a directional function; for paralyzed patients with muscle disorder, the selection function can be realized more easily; and so on.

In some configurations, the input and output lines of position measurement system 20 and conventional keyswitch matrix 5 are optimized to be tied together so that the pin count is minimized, or by way of example, does not even increase the pin count beyond all pins required by a conventional keypad alone.

Referring to fig. 2 and 3, the dashed lines are traces contained within the PCB and are shown in dashed lines, traces on the surface of the PCB are shown in solid lines, and vias or holes connecting the two layers are shown in dotted lines. An integrated vertical array 23 is placed on the surface of the PCB 12 (to reduce the number of vias) forming half of the keyswitch matrix 5, as well as a vertical array of position measurement systems. Likewise, the integrated horizontal array 25 forms the other half of the keyswitch matrix 5, as well as the horizontal array of the position measurement system. In this case, the array 25 is placed within the PCB 12. A switching grid spacer 18 is placed at each intersection of the arrays 23 and 25, each formed by an interdigitation of bare elements on the surface of the PCB, thus forming a capacitive grid element for the position measurement system 20, into which half of the plurality of switching grid spacers are integrated. Each column in fig. 3 represents a different design of the shim 18. The leftmost column shows a grid spacer 18 formed with contact element switches designed to use dome contact switch technology. The second column to the left represents cross-pads formed with individual vias. The rightmost column shows the first elements 19 (three drawn per grid pad) interconnected by short vertical elements placed on the PCB surface of the leftmost element of the array 23, and short vertical elements placed inside the PCB of the other two elements of the array 23. The second element 21 is interdigitated with the first element 19 and connected to each other by associated holes or vias with an integrated horizontal array 25. In each case, the elements of the switch grid pad 18 are symmetrically positioned relative to the elements of the position measurement system, thus providing a signal with self-canceling capability, without compromising the accuracy of the position measurement system 20 despite the integration of the keyswitch matrix, thus enabling a consistent output to be measured independent of the direction of finger proximity to the switch.

Input 31 comprises signals injected into the integrated horizontal array 25 and output 33 comprises signals received by the integrated vertical array 23. Thus, the total number of pins required by the microprocessor or analog-to-digital converter to meet the conditions of signal input to the microprocessor is the same as that required by a conventional keyswitch matrix alone.

The change in parasitic capacitance across the switch grid pad 18 may also be used to detect the proximity or approach of a finger or conductive ball. This may provide additional information for resolving ambiguities, as an example.

In the keypad of FIG. 4, the IACK element 10 does not have the conductive pellets of the embodiment shown in FIG. 1, but instead is coated with a force-sensitive material 13, such as conductive non-contact particles. For example, material 13 may be a material such as those that produce quantum tunneling effects found by Peratech Limited of Darlington, Daltoma county, UK.

In the embodiment shown in FIG. 5, the IACK keypad is not implemented with a conventional keyswitch matrix. The position measurement system 20 provides icon control and keypad input functions. The high degree of non-linearity of the capacitance measurement, and the ability of the device to determine the maximum extent of any given user, and to determine finger extension by measurement of the nearest intersection point, allows this embodiment to operate without any unique keypad switch matrix. If the finger is close, thereby increasing the magnitude of the measured capacitance, the system determines the approximate size of the finger by comparing adjacent intersections on a relative scale. That is, since the trajectory of the finger movement passes through the keypad from one location to another, through a plurality of nodes, when the finger does not change sufficiently in height, a range of capacitance values is formed at these locations. This range is then compared to a reference value, such as a look-up table of absolute dimensions, to form the size of the human finger, and an appropriate capacitance measurement level is determined therefrom for use in measuring recognition of the intended input (e.g., pressing a keypad) based on the position of the finger and the size of the finger when the appropriate expected input threshold is reached.

In the embodiment shown in FIG. 6, an integrated horizontal array 25 is disposed within the PCB 12 and a vertical array 23 is disposed on the lower surface of the IACK element 10, the arrays preferably being printed with conductive ink. The horizontal array 25 may also be placed on the surface of the PCB 12, covered with a thin non-conductive layer, which may be formed of, for example, 0.01 inch KAPTON material (typical polyimide), available from DUPONT. The advantages of the embodiment represented by this figure over the embodiment represented by figure 5 are: the capacitance change measured on the activated key is improved. If a finger is moved across the surface of IACK element 10 (without pressing a key), the change in parasitic capacitance measured by the device provides coordinate position information. When the desired character is pressed in the keypad mode, a larger change in capacitance is caused because the traces of the capacitive array may move relative to each other. This high variation in capacitance is different in magnitude (order) from those of the measured parasitic capacitances and therefore clearly indicates the intended key activation. The system then registers the recognized character with the parasitic capacitance change measured prior to the change in the large indicative activation. Thus, the two measurement systems used cooperate to provide a particularly robust (robust) icon control and keypad system. An additional advantage of this design is that, despite providing additional functionality, it can be configured to require fewer microprocessor pins than a conventional keypad matrix. For example, the number, arrangement and spacing of the array traces need not coincide with the keypad's keypad in some embodiments, as is illustrated by the arrangement of the rightmost elements in the array 23. As an example, the pitch of the capacitive grid may be greater than the pitch of adjacent independent key regions.

Fig. 7A shows a keypad having contact elements formed from an array of piezoelectric devices 30 of the variable height type, as disclosed in U.S. patent nos. 5,781,646, 5,849,123, and 5,831,371, incorporated herein. As a corollary to its application, this embodiment adds energy to the device as well as a high degree of tactile feedback. However, this embodiment may exhibit multiple tactile "clicks" associated with individual combination key outputs. FIG. 7B shows an array of devices 30 formed by placing a single piezoelectric element 32 under the entire IACK element and over the position measurement system 20. This embodiment may provide a number of advantages, such as the ability to provide a single "click" on a combination key input, and the ability to provide a "received call" vibrato signal by properly activating the position/voltage transducer element 32 as detailed in the prior art.

FIG. 8 shows a keypad with a force sensitive resistor 32a, such as provided by Interlink of Canmarilo, Calif., placed between the IACK element 10 and a mechanical backing 33. The contact element is designed to be depressed very easily, replaced by a bellows with a valve that opens under a predetermined pressure, or removed entirely as shown, since the tactile feedback is provided by a vibrating element 40 that is momentarily activated by a controller 42 to indicate receipt of an output from the keypad. The illustrated vibratory element 40 is a vibratory motor such as is commonly used for telephones, paging, etc. to indicate an incoming call or page.

FIG. 9 shows the PCB 12 of an IACK keypad with a pair of electrical traces 69a and 69b providing contact for all switches in the matrix.

Referring now to fig. 10 and 11, the IACK element is fitted with conductive pellets 16 having flat outer contact surfaces 16a in the shape of a cross in which the ends 52 of the legs 17 extend toward the associated combination keypad 3. As an example, each ball 16 is placed directly below the independent keypad 2 of the keypad, extending a distance d in the direction of extension₁，d₁Corresponding to the distance d from the center of the conductive ball 16 to the center of the combination keypad 3 to which it extends₂About 40 percent. In this embodiment, each of the terminal edges 52 is positioned approximately along a line segment connecting the centers of the closest contact elements 14. The edges of the remaining conductive balls 16 are preferably displaced from each adjacent contact element by at least one-half of the contact element click length "s", where "s" is defined as the vertical distance that the contact element 14 extends beyond the conductive ball 16. The contact areas 67 are areas of the independent keypad that, in operation, act as buttons, in the sense that they transmit the force of the operator's fingers as a curvature of the keypad surface and do not include areas that are reached by incidental, unloaded contact with those operator's fingers. Thus, in the case of separate independent key regionsDuring operation, the contact region 67 transfers nearly all (e.g., ninety percent) of the load provided by the user. The relationship between contact area 67 and the preferred pellet shape is explained with reference to fig. 20A and 20B. The exposed upper surface of the keypad shown in fig. 11 corresponds to the keypad profile shown in fig. 28.

Fig. 12 and 13 illustrate a different configuration of the conductive pellets 16. In this embodiment, each bead forms an extended cross, with the cross support 17 extending further toward the combination keypad 3 than in the embodiment shown in FIGS. 10 and 11. In this example, the cruciform shelf 17 extends a distance toward the adjacent combination keypad 3 of about 75 percent of the distance from the center of the conductive pellet 16 to the center of the combination keypad 3, with the end shelf edge 52 lying beyond the adjacent contact element 14. This can be used to create important advantages, which can be explained with reference to fig. 20. The central region 54 of each bead is substantially flat and parallel to the plane of the keypad, and the support 17 tapers at about 10 to 20 degrees relative to the plane. The remaining conductive ball edge is displaced from the contact element 14 by at least half of the click length, which is defined as discussed above with respect to fig. 11.

Fig. 14 illustrates a side view of a thin layer (sheet)58 of solid conductive material into which the conductive pellets 16 of fig. 12 and 18 may be pressed as an alternative to printing conductive ink on the surface of the as-cast IACK element 10. The thin layer 58 may be formed from a sponge-like carbon coating or a resilient plastic material or other printed conductive material, extruded or otherwise cast to form one or more intersections having an undulating surface as shown. Individual pellets are then pressed or stamped from such a thin layer. The balls being pressed in have a symmetry such that the balls can be directed upwards or downwards during the manufacturing process, the elastic material complying with the requirements of the adjustment, thus making the manufacturing process easy.

Fig. 15 illustrates the switch grid pad 18 structure for the conductive pellets 16 in the embodiment shown in fig. 12, with light emitting diodes 56 placed in the combination keypad 3 between the grid pads.

Referring now to fig. 16 and 17, IACK member 10 is shown with contact member 14 positioned below combination keypad 3. The conductive pellets 16 are shown below the independent keypad 2. In this example, the upper surface of the keypad is as shown in fig. 29. Preferably, the end corners 52 should present straight edges that diverge with respect to the combination keypad 3. In this embodiment, a chamfered right-angled corner is selected. By way of example, each ball 16 is positioned directly below the keypad's independent keypad 2, on a line connecting the centers of adjacent keypads, extending a distance d in the direction of extension₁，d₁Corresponding to the distance d from the center of the conductive ball 16 to the center of the combination keypad 3 to which it extends₂About 40 percent. The exposed upper surface of the keypad shown in fig. 17 corresponds to the keypad profile shown in fig. 29.

Similar to fig. 12 and 13, fig. 18 and 19 show the pellet 16 extending farther toward the combination keypad 3, but with the peripheral region of the pellet angled away from the PCB 12. In this case, as illustrated, the ball 16 has a flat, horizontal central region 54, but in other embodiments (not shown) the entire contact surface of the ball 16 is sloped or curved to produce the desired result. The contact element 14 is as described above.

Fig. 20A and 20B illustrate the bending of the keypad overlay causing the ball 16a associated with the depressed key 2a to make contact with the PCB 12, while the adjacent ball 16B associated with the other keypad 2B is slightly tilted with respect to the PCB but does not make contact. As shown in the previous figures, the point of intersection is on the major axis of the pellet. The ball shown in fig. 20A is the same as the embodiment shown in fig. 10 and 16, while the ball shown in fig. 20B is tilted as in the embodiment shown in fig. 12 and 18. If the user desires a character printed on the keypad 2a, she brings the ball 16a into contact with the PCB 12; if she needs the characters printed on the keypad 2b, she touches the small ball 16 b; if she desires to have the characters of the combination keypad 3 printed between them, she will have a meaningful squeeze of the beads 16a and 16b against the PCB 12. In all instances, the independent key regions 2b are slightly bent, partly because of the necessary coherence caused by the bending of the common membrane forming them, partly because of inaccuracies inherent in normal use. Therefore, if the opposite edges of the two beads extending toward the combination keypad are too far apart, a very small fingertip may cause a curvature of the surface of the keypad corresponding to the combination keypad without pressing down the two beads, and thus the desired combination keypad may not be registered. Conversely, if the opposing edges of the bead between two immediately adjacent independent key regions are too close together, a user may accidentally cause a click on an adjacent independent key region when pressing only on a single independent key region, thereby erroneously registering a combination key region input. The illustrative embodiments solve this problem by efficiently sizing the pellets. By tilting the end regions of the contact surfaces of the beads, as shown in figure 20B, they can be made larger, thus providing reliable operation with small or large fingers. This improvement also helps to enable the independent keypad 2 to be made relatively small while allowing the pellets to remain relatively large.

Figure 21 illustrates a two-dimensional array of equally spaced contact elements 14, each positioned approximately midway between the beads 16 associated with two adjacent independent key regions 2. In this embodiment, the contact element 14 is cell-shaped, but it should be understood that shapes other than this particular shape can provide approximately the same non-linear clicking effect. The contact elements form an alternating array, with each space between the contact elements accommodating either a ball 16 associated with the independent keypad 2 or a space associated with the combination keypad. Each independent keypad and combination keypad (i.e., the spacing of each contact element) is equally configured relative to the number of adjacent contact elements and their proximity such that a user will experience a similar tactile response from the activation of the independent and combination keypads because an equal number of contact elements 14 are depressed during each operation. In this example, the conductive pellets 16 are shown as annular discs, but may be formed in other shapes as described above.

In contrast, in the embodiment shown in FIG. 22, the tactile feedback for each combination keypad 3 is provided by four equally spaced adjacent contact elements, while the tactile feedback for each independent keypad is provided primarily by a single associated contact element 14 located directly below the independent keypad 2. Each contact element 14 surrounds an associated conductive pellet 16. This arrangement is configured to: the activation force of the combination keys may be provided approximately four times greater than the activation force of the individual keys if desired for a particular application. However, for many applications it is desirable to provide similar haptic feedback responses for all keypads, such as provided in the embodiment shown in fig. 2 and 21, where each contact element 14 is placed at a nearly equidistant position of two adjacent independent key switches. In this case, the contact elements 14 may be cross-shaped.

Fig. 23 shows a schematic diagram of a mobile phone control circuit for performing mobile phone functions, including those keypad control algorithms disclosed herein. At its heart is a telephone processor 89, such as chip ML20xx available from Mobile Link of Santa Clara, Calif. Flash memory 90, static random access memory 91 and liquid crystal display 92 are connected by a bus to an ARM RISC (reduced instruction set computer) processor 95 of chip 89, which provides a user interface and protocol routines. Wires connect the system connector 93, the SIM (subscriber identity module) 94 and the keypad 100. An Oak Digital Signal Processor (DSP) on chip 89 provides the physical layer for processing the voice, which is transmitted and received by the dual band RF unit 96, through a microphone 97 and speaker 98.

Referring now to fig. 24, a mold pair (mold half)44 includes a mounting plate 15 defining a cavity 46 for casting the outer surface of each contact element; and a moving plate 47 with approximately conical projections 48 forming the inner surface of the contact elements, the mold being used to form the lower surface of an IACK keypad with integrally molded contact elements as shown in fig. 14. As the resin is injected, the two mold plates are snapped together and cooled, and then separated so that the cast contact element is removed from the hole 46. Holes 48 are also provided in the plate 45 to act as inserts to support the conductive pellets during the casting process. If the bore 46 were to descend perpendicular to the intersection of the resin flow to a region toward the end of the bore, the moving plate 47 and the fixed plate 45 could be permanently bonded together so that the cast contact elements could be ejected from their cavities without the need to separate the mold pairs.

Figure 25 shows a tactile feedback structure for a keypad having an array of linear guides 62 molded into a common base 63 and extending at an angle of approximately 60 degrees relative to the base. Alternatively, the guide rail 62 may be a belt or a curved shape, curved across the surface of the base plate 63 like a snake. This embodiment provides non-linear tactile keypad feedback over the entire IACK keypad surface. The substrate is glued to the printed circuit board with an adhesive and the holes 65 provide space for the balls of the keypad to contact the PCB. Alternatively, the guide rails may be integrally molded, in whole or in part, with the lower surface of the elastomeric keypad overlay. Affixing the ends of the rails to the opposite surface (on the keypad or PCB) prevents the center of the IACK keypad from deforming under temperature and humidity variations while providing a stable reference to the ends of the feedback element.

Fig. 26 shows a side view of a keypad with a tactile feedback element 210 formed from a stamped metal film placed between the overlay 10 and the PCB. The film 210 is stamped to form arcuate segments 212 that extend out of plane to form contact elements. In this embodiment, the rear surface of the membrane is in face-to-face contact with the back of the IACK element 10, with the end portion of the arch segment adjacent the PCB 12. As shown in fig. 27, the arcuate segments 212 are arranged in rows and columns between the punched holes 214, providing access for the conductive pellets 16 to the PCB 12.

Referring now to fig. 28, a friendly ergonomic IACK keypad 80 having a continuous undulating surface that is substantially free of visible voids representing the combination keypad 3 as the independent keypad 2. Instead, the combination keypads exist as completely separate entities (although they are still functionally interstitial). No visible components extend to the visible combination keypad 3 to indicate any association with the independent keypad layout. In this embodiment, the combination keypad has a smooth outline, visible oval bounded area, each with a centrally placed icon thereon. The independent keypad 2 is not depicted and thus provides a visually clear and concise textual environment that enhances legibility and allows for a conventional telephone key layout by utilizing the primary graphical elements. The graphical elements may be lightly pressed in and/or manufactured using a "two-shot" molding process, wherein the elements defining the combination keypad 3 (or a conventional telephone layout alone) are molded first in one color and the rest of the keypad is molded in a second color.

Fig. 29 shows an IACK keypad 82 in which the combination keypad 3 is maximized into a circular or oval area and the independent keypads 2 are formed by diamonds 64 placed in the spaces between them. As shown in fig. 28, the combination keypad is not shown in this embodiment as an intersection of the independent keypads. Instead, the combination keypad appears as a separate entity. The expanded circular or oval shaped areas associated with the combination keypad 3 are extruded as a bowl shape with a depth of about 0.10 to 0.50 mm at their center, measured from a neutral plane defined by relatively sharp changes at their edges. Referring again to fig. 19, the raised portion is a diamond shaped bump 64 that extends approximately 0.30 to 1.0 mm above the neutral plane. Thus, the entire distance d from the top end of the diamond shaped bump 64 to the bottom end of the circular or oval shaped area representing the combination keypad 3₃Approximately 0.7 to 1.5 millimeters. The top of the bump 64 is mainly flat and slightly curved. The combination keypad 218 is equipped with a pair of tactile location nodes 101, such as for example the number "5" in many standard keypads. In addition, just outside the keypad grid of combination keypads, between the fourth and fifth rows (i.e. aligned with the fifth row of independent keypads) counted from the far end of the keypad, there are located two accessory positioning nodes 103. These positioning nodes can be used to assist in touch positioning in the dark when using a keypad or by visually impaired people.

Fig. 30 shows the underlying grid associated with the individual keys, defined by the switch matrix under the keypad overlay, with dashed lines indicating no operator visible depiction of this functional grid on the exposed surface. Instead, the surface of the overlay has a matrix of individual and composite key areas defined by the graphic or sensitive components arranged with the underlying grid. Each dashed box defines an associated independent key grid space. Instead, the combination key grid space is defined between grid lines connecting the independent key regions.

Fig. 31 through 33 illustrate an IACK keypad 10 with a conventional telephone layout formed by columns of numbers formed by the combination keypad 3. First digit column 70 (with 1, 4, 7, ") is separated from second digit column 72 (with 2, 5,8, 0) by a column 74 formed of unrelated characters (illustrated here as punctuation. Between the second and third digit columns, use),: the second punctuation column formed repeats this pattern. The icon areas of adjacent columns of combination keys (e.g., 70 and 74) have different widths, ranging from wide (column 70) to narrow (column 74). One regular keypad pitch is represented by the cross section of the immediately adjacent independent keypad 2 (fig. 32), and the other keypad width is represented by the cross section of the immediately adjacent combination keypad 3 (fig. 33). Preferably, the width "X" representing the spacing between immediately adjacent independent keypads 2 is about half or less the width of a human finger, and the color of the icon area is used to identify the characters in alternate columns, for example, from dark to light contrast.

Fig. 34 illustrates an IACK keypad with columns of independent keypads 2 and columns of combination keypads 3 arranged along a 45 degree offset angle relative to the user (i.e., relative to the standard keypad orientation defined by the orientation of the icon). This embodiment increases the number of independently activatable keys that can be arranged in a horizontal line (as defined by the standard keypad orientation) by approximately 40 percent relative to some earlier keypad implementations, thus significantly reducing the width of the keypad product, particularly the illustrated conventional QWERTY layout.

FIG. 35 shows an improved method for interpreting long string form (LSC) entries, such as telephone numbers, passwords, personal identification numbers (PINs; codes for identifying access or services provided by a personal priority access system), etc., that takes advantage of the capabilities of the IACK keypads disclosed above to simultaneously detect entry of even non-adjacent keypads in any combination of independent keypads. This method has the advantage of providing a secure and fast method for entering a digital code, which can be used, for example, in: providing access to web sites and other telephony services and content; entering its phone number before the PIN to access the voicemail; and so on. These algorithms, called LSC functions, are adapted to simultaneously satisfy the following requirements: 1) generating sufficiently complex inputs to provide a reasonable level of security; 2) in many different applications, the minimum requirement for PIN access codes is met; and 3) LSCs that allow for near-simultaneous input, whether user-defined or system-defined.

In step 100, the system scans the keypad's electronic device for two or more independent keys that are pressed at any particular time. In step 102, the system displays the characters, e.g., on a local display, in the order in which the system identifies the defined combination keys corresponding to the sensed combination. Preferably, the user does not need to separately perform any task of obtaining LSC functionality; to prompt the system to take the LSC function within a predetermined time, an undefined combination of at least two independent keys is simply pressed. If the system detects an undefined combination, the system proceeds to step 104. If the system has just registered a single or combination key before a defined combination is identified and no "key up" is registered (i.e., the user has not stopped pressing the keypad), the system cancels the previous character entered.

In step 106, the system determines whether the undefined combination corresponds to a stored LSC. If it has been previously stored, then in step 108, the system sends the associated LSC to the display screen. If a previously undefined combination is not stored as a corresponding LSC, the system determines how many characters are registered on the display when an undefined combination is sensed in step 110. If the characters are registered, but too short (e.g., one or three) for the number of PINs to be valid, the system prompts the user that the PIN must be at least four characters long and continues to scan the keypad in step 100.

If there are no characters on the display screen, a pseudo-random LSC is initially generated based on the input system provided. In step 111, the system sequences the individual key inputs (in this embodiment, the combination keys are not read in their meaning when the defined combination is established) into a predetermined order that is independent of the order of the individual key inputs that is sensed. One such order is alphabetical. The other (including punctuation) is ordered by ASCII value. This sequence may change the order in which keys are retrieved by the system. In step 112, the system generates an LSC string, preferably all numbers and at least 8 characters long. If a simple string of ASCII values causes an LSC that is too short, the numbers can be added together and the result increased. A suitable pseudo-random number sequence may be generated from a series of inputs in a variety of ways. If the result is too long, it can be truncated.

In optional step 114 (e.g., if used while a telephone call is in progress), the system determines the identity of the other group by checking the caller's ID, or simply searching for the identity of the other group in a stored address book. If, in step 110, it is determined that the user has entered a meaningful LSC on the display, (in this example four or more), the system stores this defined combination in memory so that the associated LSC can be provided in step 108 in the future. In step 118, the LSC is fed into the display screen 92, whether user-defined or system-defined. In the case of a system-defined LSC, a reference identification code, such as "PIN # 3", or (if step 114 is completed) a specific user identification code, such as "Bank X PIN", will be passed.

Fig. 36 shows an algorithm embedded in the phone that provides an inverse mapping from the input of the alphanumeric keys to the output of the numeric keys, according to the correspondence indicated by a standard 12-key telephone keypad (i.e., the alpha-numeric correspondence of a standard telephone keypad, as shown in fig. 37), which simplifies the task of dialing telephone numbers provided in alphabetical form, such as "1-800-PATENTS". Such numbers have been difficult because they are easy to remember but difficult to dial. However, inverse mappings are particularly suited to IACK keypads, because although they provide a telephone keypad, in many instances they do not provide correspondence between alphabetic and numeric character keys.

In step 120, the user enters alphabetic data into the phone. This can be done with a conventional keypad, IACK keypad or voice. In step 122, the user signals a desire to "dial out" a telephone number by pressing a key or speaking a predetermined word. Steps 120 and 122 may be reversed in order, particularly in the case of speech. In steps 124 and 126, the phone may pass numbers unmodified in any order, with the alphabetic characters being remapped by the standard alphabetic phone correspondence shown in FIG. 37. For example, when any one of the letters "a", "B", or "C" is pressed, the number "2" is output. In step 128, the output of the algorithm is pure numbers, all formed by a combination of numbers.

Fig. 38 shows a layer of resilient material 122 that provides tactile feedback over the entire IACK keypad surface using discrete elements 222 that are assembled with the keypad and extend between the cover layer and the base layer. These elements 222 extend in a perpendicular direction relative to the substrate 220 (as shown), and operate in a pure click mode when the overlay is depressed or tilted toward the underlayer. The element 222 may be a solid cylinder or a vertical cylinder.

FIG. 39 shows the contact element 14 cast with the common layer 61 separated from the IACK element. The contact elements 14 are tapered with their narrow ends 230 pointing downwards, away from the cover layer 10. Additional thickness is provided at the narrow end 230 to form a block of material to enhance the "click" or crisp feel of the tactile feedback provided by the original.

Fig. 40 shows a scan algorithm that can support a particularly slow scan rate of the clock, thereby saving power. As long as one key on the keypad is activated, the scanning is limited to adjacent keys. If the second key switch is activated during the waiting time, the system searches for the rows (or columns) above and below (adjacent to) the activated pair of switches. This process continues until a single key is activated for the duration of the wait, or until the opposite diagonal is detected.

Fig. 41 shows a printed circuit board 12 with traces 226 in the keypad grid area at a 45 degree angle to the outline of the board. The dashed lines represent traces that connect to the center ring of the dome contact switch 228. The solid lines represent traces connected to the outer rings of those switches. This arrangement provides a simplified recognition algorithm since the individual keys located adjacent the opposite diagonals define the combination keys. This hardware changes the redefinition of the software so that the simultaneous output of adjacent traces represents the output of the combination keypad.

In fig. 42, the rows of independent keypads 2 are formed in an arcuate slanted arrangement defined by radius "R" to help identify the location of the touch induced cross-keypad, while their corresponding keyswitch pads 18 remain arranged along vertically distributed rows and columns, causing a vertical offset "L" between the centers of independent keypads 2 and their switch pads 18 on a particular column. In the forward view, the independent keypads are slightly above their switch pads in the leftmost and rightmost columns, while in the middle columns, a reverse offset is formed. This allows the switch matrix pitch to remain constant, even though the pitch between adjacent independent key regions on the diagonal varies.

Referring now to fig. 43 and 44, a mobile phone 250 includes a keypad overlay 82 as shown in fig. 29 and 30, and a display 92 for displaying alphabetic text.

While several embodiments of the invention have been described, it will be appreciated that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the invention.

Claims (2)

1. An IACK keypad having combination key regions and independent key regions defined in alternating columns, with a standard orientation defined by icons associated with the independent and combination key regions, wherein

The alternating columns are arranged along a line that is inclined at an angle, depending on the standard orientation of the keypad.

2. The IACK keypad of claim 1 wherein said angle is approximately 45 degrees.