Patent Application
20080202824
The invention relates to control panels for controlling a device in response to a user's input, in particular the invention relates to a control panel having both touch sensitive and mechanical input means.
There is an increasing demand for compact and user-friendly control panels for many devices, for example for devices such as portable media players, digital cameras, mobile telephones and so forth. These devices are becoming smaller and are being provided with more functionality. To make best use of this increased functionality it is important that the control panel presented to the user (i.e. the user interface) is ergonomic, simple and intuitive to use, and allows the user to quickly access the functions of the device. There is also a demand for control panels which are both aesthetically pleasing and robust yet simple to manufacture.
It is known for control panels to include both touch sensitive inputs (e.g. capacitive position sensors) and mechanical inputs (e.g. conventional push buttons/switches). For example, the “iPod mini” manufactured by Apple Computer Inc. has a touch sensitive scroll wheel overlaying a number of switches.
The capacitive sensor 6 is formed on a platform printed circuit board (PCB) 10. The platform PCB 10 and the capacitive sensor 6 are covered by an outer protective layer 14. The platform PCB 10 is tiltably mounted on a central support 12 so that it can move within an opening in the wall 4 of the device. The support 12 is attached to a base PCB 16. The base PCB 16 and the wall 4 are fixed together. The position of a user's finger touching over the sensor 6 is determined by the control circuitry and may be used to control the device.
The switches 8 are mounted on the base PCB 16 beneath the capacitive sensor 6. By mounting the switches behind the capacitive sensor instead of elsewhere on the device the footprint of the control panel is reduced. Each switch 8 comprises a deformable diaphragm 8B disposed over a central electrode 8A. Each diaphragm extends away from the base PCB 16 to a height at which it just touches the underside of the platform PCB 10. Switching action is achieved by deforming a selected diaphragm so that it contacts the central electrode 8A. This is done by pressing down on the capacitive sensor above the desired switch. This causes the platform PCB 10 to tilt about its central support 12 and compress the diaphragm of the selected switch to bring it into contact with its central electrode.
A user provides instructions through appropriate use of the capacitive sensor and the switches. For example, if the device is a portable music player and the user wishes to play a particular track stored on the device, the user might activate an appropriate one of the switches to display a listing of the tracks available, then run his finger around the capacitive sensor to scroll through the available tracks, and finally press another of the switches to start playback of the desired track. A center button is often included as well for additional forms of input to activate a function, as described in US Patent Publication 2003/0095096.
Although the control panel 2 shown in
Another kind of control panel is described in the applicant's patent U.S. Pat. No. 7,279,647 as shown in
The control panel 22 comprises a PCB substrate 36 carrying the capacitive sensor 26 and the switches 28, a surface panel 24 overlaying the substrate 36, and an outer protective flexible membrane 34. The plastic surface panel 24 is integrally formed in a wall of the device. The sensor 26 is in the form of an annulus and comprises areas 27 of conductive material deposited on the substrate 36. Four of the conductive areas have circular open regions 31 within which there is no conductive material. These open regions 31 correspond to the positions of the four switches. Within each open region 31 is a central electrode 28A which acts as a switched contact of the corresponding switch. An electrical connection 42 passes from each central electrode through the substrate 36 to allow the switched terminal to be connected to sensing circuitry.
The control panel 22 is connected to position sensing circuitry operable to determine a capacitance distribution within a sensitive area of the sensor. An object, such as a user's finger, in the vicinity of the sensor 26 affects the capacitance of each of the conductive areas differently depending on the position of the object within the sensitive area. Measurements of the capacitance to ground of the respective conductive areas are taken, and from the changes in capacitance caused by the presence of the object, the position of the object on the sensor is determined. A control signal representing this position is reported to a device controller which takes appropriate action to control the device.
Each of the four switches 28 comprises a deformable conductive diaphragm 28B disposed over a respective one of the central electrodes 28A. When the diaphragm 28B is in a relaxed state (i.e. no deforming force applied) it does not contact the central electrode 28A and the switch is in an open state. The diaphragms 28B each extend through their respective holes in the surface panel 24 so as to protrude above it. The flexible protective membrane 34 is in the form of a ring and is attached to the surface panel 24 within the recess in its upper surface so as to overlay the protruding diaphragms.
Switching action is achieved by a user pressing above the appropriate diaphragm 28B to compress it sufficiently to bring it into contact with its central electrode 28A, thus placing the switch in a closed state. This is done by pressing down on the flexible protective membrane 34 at the appropriate place. The circuitry is configured to respond to this by sending an appropriate control signal to the controller so that it can take appropriate action to control the device. This configuration has the advantage over the design of
The control panels illustrated in
Other control panel systems are known which allow a user to control a device. For example International patent application WO2006029974 discloses a system which includes a touchpad and means for determining the location of a point at which a user touches the touchpad. The system is further arranged to provide a user with mechanical feedback if a force applied by the user on the touchpad exceeds a certain value. This is achieved by moveably suspending the touchpad within a frame and detecting movement of the touchpad within the frame upon the application of pressure. The system does not disclose or suggest any arrangement in which a location of a point of contact and a pressure applied at the point of contact can be correlated. Furthermore, because the touchpad is physically separate from the frame, gaps are left which leave the touchpad and the frame vulnerable to penetration by dirt and liquid.
U.S. Pat. No. 6,239,790 discloses a touchpad assembly for providing a signal to a computer indicative of the location of pressure applied by an object touching the touchpad assembly. The touchpad assembly includes X and Y position and pressure sensitive layers formed from semiconductor resistance sensors. Although the arrangement can determine a position and a pressure applied by a user input, the system is complicated. Moreover, the system is concerned primarily with measuring a continuous range of input pressures and because the system is implemented using semi-conductor sensors, the range of detectable input pressures that can be accurately detected is limited.
US2007/0052691 discloses an input device, which includes a movable touchpad. The device includes means for determining a point at which a user touches the touch pad and means for generating a control signal representing the point at which the user touches the touch pad. A group of movement indicators detect the movement of the movable touch pad so as to generate a number of additional control signals, which indicate the movement of the touchpad. Although enabling both the position of a user input and the movement of the touchpad to be detected, this system does not enable the detection of an individual actuating pressure, which can detect a user input pressure above a pre-determined threshold value. Furthermore, the disclosed system requires a number of movement sensors to detect the movement of the frame, which can add to the cost and complexity of the input device as a whole. In addition, since the touchpad is physically separate from the rest of the device, gaps are left which leave the device vulnerable to penetration by dirt and liquid.
US2004/108995 discloses a system including a touchpad integrated with a display unit. The display unit is attached to a mechanical system which allows the display unit to be moved relative to a frame which contains the display unit. When a user touches the touchpad, the position and the pressure with which the touchpad has been touched is detected and the display unit is moved accordingly. As such the mechanical system provides an arrangement for moving the screen in a direction in which it is being pushed.
To address the short comings of the prior art documents mentioned above an improved control panel has now been developed.
According to a first aspect of the invention there is provided a control panel comprising a position sensing element (“PSE”) coupled to a position interface circuit (“PIC”) operable to determine the position of an object applied to the PSE, and at least one pressure sensing device (“PSD”) below the PSE, wherein the PSD responds to user pressure applied at multiple locations on the user-operable user surface. The PIC or the end application determines the nature of the user's pressure input; for example by interpreting the pressure sensed by the PSD as an ‘enter’ or ‘make it happen’ function correlated with a user feedback display such as a menu item on an LCD, without the need for moving or lifting a finger off of the PSE to a discrete button location. The PIC can also provide this correlation by having knowledge of the user's finger location at the moment of a PSD pressure increase.
Thus according to the first aspect of the invention, in one example, the pressure event in which the object is applied to the sensing surface of the PSE with a pressure, which exceeds an activation pressure threshold, can be detected by the PSD even though the object is applied at any arbitrary position on at least part of the sensing surface of the PSE. In some examples, the PSE is displace-ably mounted with respect to the PSD so that pressure applied by the object above the activation threshold causes the position sensing element to be displaced with the effect that the pressure event can be detected by the pressure sensing device. Another aspect of the invention includes a user controlled device having a control panel according to the first aspect.
The PSE may be impedance-based, for example capacitive or force sensing resistive (“FSR”), or non-impedance based such as optical or acoustic methods. It is preferred that the sensor layer is a capacitive PSE capable of interpreting a user input as either a one or two dimensional touch location depending on the requirements of the application. Both relative and absolute position measurements by the PSE are acceptable in various embodiments. These sensor types are well known in the art and are not described in further detail herein.
The PSD may be a deformable dome switch providing a galvanic contact closure upon being compressed which can be read by the end application processor or by the PIC. Conveniently this type of PSD can provide the user with a mechanical click feedback upon being pressed. Other types of PSD can be employed, for example a FSR, optical interrupter, piezoelectric crystal, or capacitive switch operable by sensing two conductive plates moving relative to each other at the moment of pressing. Such non-galvanic types of PSD have the advantage of high longevity, since they do not suffer from corrosion, oxidation, or moisture effects which can affect the reliability of the PSD. However if the PSD does not provide a click feedback to the user, a haptic device may be used to provide a mechanical feedback such as a shaking or impulse motion upon the user's pressure input to the PSD.
A ‘deformable dome switch’ should be interpreted to mean any type of switch of any composition without limitation, for example metal dome switches, conductive rubber domes, conductive plastic domes, tact buttons, membrane buttons, or other electromechanical switching devices, with or without tactile feed back.
The control panel may further comprise a substrate or support in which the PSE is mounted thereon. The PSD may be positioned below the support and is arranged to change between an open state and a closed state by pressing and de-pressing the PSE mounted on the support.
The control panel may further comprise means for holding the support on which the PSE is mounted within the control panel. The control panel may also comprise means for controlling displacement of the support, such as for example spring means, between positions in which the PSD is in an open state and a closed state. In a preferred embodiment, the means for holding and controlling displacement of the support are unitary.
The control panel may comprise a flexible or deformable surface panel overlaying the PSE, and with the PSE overlaying a PSD via a mechanical structure such as a moving platform. Furthermore, the control panel may additionally comprise a protective flexible membrane overlaying the surface panel. This provides for a control panel having an outer surface which is in effect sealed but still allows for activation of the PSE and the PSD. Sealing may also be provided using gasketing around the perimeter of the movable portion of the device.
The PSE can be arranged along any desirable path, for example, a closed path such as a circle or an open path such as a line or curve. Similarly, the PSD may be positioned at a location under the PSE as desired. Furthermore, the control panel may be provided with additional mechanical or touch sensitive switches outside of the sensitive area of the PSE.
The control panel of the invention may be in the form of a rotary panel (i.e. the PSE is arranged in a circle or curve such as a half-circle or an omega shape), a tilt pad or track pad (i.e. the PSE is arranged to have a square, rectangular, oval or other suitable shape). A capacitive PSE may be comprised of single or multiple conductive electrodes, e.g. copper, carbon, or clear Indium-Tin-Oxide (ITO) electrodes, arranged in a predetermined way. An ITO based capacitive PSE can be used to provide for a transparent or translucent PSE which can be backlit or placed in front of a graphical display such as an LCD or LED display. Thus, the PSE may be arranged to be opaque or substantially transparent depending on the application of the device incorporating the control panel.
In embodiments of the invention, the PSD used may be arranged to be single force or dual force. If the PSD is single force, then applying a force sufficient to change the state of the PSD will activate a required mode or function (such as “enter” or “make it happen”) of the device incorporating the control panel. If the PSD is dual force, then applying a force sufficient to cause a first or ‘initial’ pressure input followed by an additional force or press on the PSE to cause a second or ‘final’ pressure input, two functions or stages of a function may be controlled on the device. An example would be where a user scrolls to a menu item or function using the PSE surface, then presses lightly to activate the first pressure input stage causing a ‘preview’ of the selected function; an even harder user pressure can then ‘make it happen’. A controller can interpret the signals from the PSD to determine the function or operation required based on the operating software used in the particular device.
The PSD may allow for displacement during a pressure event, for example a tactile dome will compress under pressure providing a click feedback feel. However the invention can also employ non-displacement type PSD's such as FSR's and piezoelectric sensors; these types of PSD do not offer a tactile click feeling but can provide for a mechanism that offers better panel sealing against moisture and dirt. Tactile feedback in these cases can comprise a haptic transducer which is responsive via the PIC to provide a click or shaking response to the user.
The control panel of the invention may be incorporated into consumer electronic devices, such as for example, mobile telephones (cell phones), portable media players (MP3 players), digital cameras and so on to control different operating functions of the devices. The control panel of the invention may also be a ‘standalone’ device or peripheral to a main device, e.g. a computer. In such embodiments, the peripheral device is electronically connected to the main device, wirelessly or by cable, to control a cursor or other function on the display of the main device. In one preferred embodiment of the invention, the control panel may operate as a mouse or other input device to a PC.
According to another aspect of the invention there is provided a control panel for controlling a device is response to user indications, the control panel comprising, a position sensing element having a sensing surface, and a position interface circuit. The position interface circuit is operable to determine a position of an object on the sensing surface, when the object is applied to the sensing surface of the position sensing element. The control panel includes at least one pressure sensing device. The pressure sensing device and the sensing surface of the position sensing element are arranged with the effect that a displacement of the sensing surface with respect to the pressure sensing device in response to pressure applied by the object is detectable by the pressure sensing device.
In one example, the position interface circuit is operable to identify one or more of a plurality of user indicated signals by correlating the position of the object on the sensing surface with a pressure detected by the pressure sensing device. The sensing surface may include a plurality of pre-determined locations, which may represent virtual buttons so that by determining whether the object is at one of the plurality of predetermined locations on the sensing surface of the position sensing element, the position interface circuit can identify the user indicated signal by correlating the position of the object at one of the predetermined locations with the detected pressure, each of the predetermined locations corresponding to one of the plurality of user indicated signals.
Various further aspects and features of the present invention are defined in the appended claims, which include a user controlled device, a method of controlling a device and a method of identifying one of a plurality of user indicated signals.
For a better understanding of the invention and to show how the same may be carried into effect reference is now made by way of example to the accompanying drawings, where like parts have the same alpha-numeric designations and in which:
a through 14d show plan views of the control panel having different outline shapes, coordinate systems for operation, and the use of virtual buttons;
a, 15b, and 15c show in sectional view one form of dual pressure sensing under different states of compression;
a and 16b show an alternate, more compact form of construction of the control panel with two configurations of electrical connections and two methods of pressure transfer to a pressure sensor;
a schematically shows in sectional view a control panel optimized for thinness and placed above an optional graphic display;
b shows in plan view the outline of the PSE of
a is an illustrative representation of a mobile personal computer, which has been adapted to include a touch sensor according to the present technique showing example keys on the personal computer's keyboard;
b is a corresponding example showing a different set of keys;
Optional seal 55 provides a moisture and dust barrier to the assembly; other forms of sealing will be shown in later figures.
In practice PSD 54 can be any pressure sensing device such as an FSR, or, as shown in
Switch dome 65 as shown can be a galvanic type, whose output is fed to the PIC 76 (
Compressible material 64 applies a restorative force to the assembly and thus slightly resists the user's finger pressure. Material 64 can be a ring of material around the total assembly 64a (
Turning now to
Dome 65 and contact 66 can optionally be of a capacitive type, whereby the surface of contact 66 or the lower surface of dome 65 is covered in a dielectric material so that no galvanic connection is relied upon. Sensor circuitry is required to read this change in capacitance; uniquely, this form of switch has extremely long life since the contact surfaces cannot degrade, since there is no galvanic contact. If the PIC is a capacitive readout type and the PSE is a capacitive layer, adding a single additional capacitive sensing channel for a capacitive PSD is a simple, cost effective method. If the change in capacitance due to the collapse of such a dome is large, then the readout of the capacitive spike can also be accomplished by feeding this signal into an existing channel of the PIC used to read out one of the PSE channels.
As shown in
One problem with the implementations of
a through 14d show, without limitation, various surface shapes of the apparatus. In 14a is shown a classic circular shape. User action thereupon can be either circular 94 (ie ‘iPod style’), or Cartesian 96. As with any user scrolling interface device, any type of motion such as gestures, scrolling action, absolute sensing, relative pointing motions, taps and double taps, taps and scrolls, etc can be used on the surface without any limitation. If the PSE extends beyond the apparatus, as shown in
Button locations 92 can be virtual in the sense that they do not correspond to actual buttons or any particular mechanism, rather, they are simply located via the coordinate information provided by the PSE 60 and interpreting PIC logic 76 (
b shows a rectangular sensing area which can also report discrete buttons, virtual buttons, angular inputs, Cartesian inputs, or any combination as would be the case with
c shows a linear or one-dimensional sensing surface 62, which shows that the surface 62 is not restricted to two-dimensional surfaces. This configuration is known in the trade as a ‘slider’ but in practice the surface can be used for either tapping or sliding motions. Again, virtual or discrete buttons 92 may be formed thereon depending on the application requirements. The device of
d shows that the sensing surface 62 can in fact be totally arbitrary in shape and is not restricted to neat geometrical patterns. Such arbitrary shapes are useful in certain constrained applications or for children's toys. Again, buttons can be formed thereon as described supra.
In general, one or more positioning sensing elements having sensitive areas arranged along any path, closed or open, or two-dimensional area can be used. Furthermore, the control panel need not be flat, but may be contoured, e.g. in the form of a simple or complex curve, so as to provide a shaped outer surface, e.g. to follow the lines of a device to be controlled.
a through 15c show the use of a two-stage user-pressure action. Such an action is well known in digital still cameras (“DSC”) where a pre-press is used to trigger a focus and adjustment stage, and then a yet harder press is used to trigger the image capture. Such two stage mechanical action can be quite useful in the invention because it can be used to give greater control or convey more information to the user prior to a ‘make it happen’ or ‘enter’ final push of the mechanism. One way of implementing this is with a dual-dome structure as shown. A first light pressure (ie touch) applied in 15a by finger 100 causes a reaction from PSE 60 alone. A second stronger pressure applied in 15b causes the outer dome 65 to collapse into inner dome 68, the resulting contact of which triggers a first appliance action (such as ‘preview’ or ‘focus’). A yet harder pressure shown in 15c causes the inner dome to also collapse, the detection of which by the PIC or appliance causes the ‘make it happen’ or ‘enter’ function to occur.
A second way to implement this type of action is to use the mechanism of
a shows yet another mechanical configuration which is simpler than those of the prior figures such as
b shows a slight modification of 16a, wherein the pressure concentrating protrusion 61 which is shown attached to the plate 81 is eliminated. Instead the PSD 54/65 has its own pressure concentrator 71 which serves to focus pressure on the PSD while also acting as a fulcrum for the motion of part 81.
a and 17b show a preferred embodiment, where the PSE 60a is adhered to the underside of the sensing surface 81. To achieve a wider scope of usage for the PSE, the PSE is extended to regions outside of surface 81, 60b. If the PSE is transparent (e.g., made from ITO or PEDOT coated clear PET film) then a display 74 can be used where normally would be a PCB 52. To facilitate the most cost effective and simplest construction of the apparatus, the PSD 54 is incorporated by attachment to the PSE rather than a surface of 52 or 74, with appendage 71 being upside down as shown to focus the pressure appropriately, as may be required; if the PSD 54 is small in diameter, appendage 71 may not even be required. Connections to the PSD 54 are therefore contained within sensing layer 60a. A tail 78 leads from the PSE to a connector 80. An optional haptic device 51 may be used for feedback, especially if the PSD 54 provides little or no tactile or acoustic feedback.
Depending on available materials, the PSD 54 itself can also be made transparent, or so small in diameter as not to materially interfere with the viewing of a display 74. If the PSE is a capacitive sensing type, then the PSD could also be capacitive, relying on compression of two conductive plates towards each other through a compression zone, which could be merely a small air capsule or small piece of foam, perhaps optically clear. The PSE 60a can be made easier to flex by cutting an annular ring out of it as shown in
It should be clear to the practitioner that a great many combinations of the foregoing mechanical drawing elements are possible depending on the requirements of the design and the cleverness of the individual designer. Any of the elements shown in any figure can be combined with other figures described herein to arrive at specific solutions, however all such combinations should be seen to be within the spirit and scope of the invention.
The use of an analog-responding PSD (such as a FSR) provides an opportunity to linearize this pressure response by setting the activation pressure threshold dynamically depending on where the pressure is applied on surface 62. Fortunately, the exact location of pressure can be known since the PSE 60 and PIC 76 can ‘know’ the finger location relative to the PSD location, and hence can adjust the pressure threshold required to activate an end-function. In this case, the compensation curve applied with respect to displacement from the PSD looks the same as the solid line 85, that is, a higher pressure is required for activation at the edges than at the center, by a factor of two. The haptic device 51 can be used to provide the required user tactile and/or acoustic response when this threshold is exceeded.
In many applications a FSR or other similar material for the PSD is desired since such materials can be screen-printed and are only some microns thick, as opposed to tact or dome switches which are mechanically thicker. In mobile phones for example, this would be a considerable advantage and may not even cost more (although a haptic device which is likely required with a FSR does cost extra).
It will also be understood that any form of capacitance measurement circuitry, if such is used to read out PSE 60, may be employed. A preferred capacitance measurement circuit is of the charge-transfer kind described in the applicant's U.S. Pat. No. 6,466,036. This type of circuitry provides for a reliable and robust measure of the typical capacitances that might be expected in a given implementation of the invention. However many other capacitive circuit types can be employed as well and do not affect the scope or spirit of the invention.
Finally, it is noted that although the term “touch” is frequently used in the above description, a PSE can be sufficiently sensitive that it is able to register the location of an adjacent finger (or other object such as a stylus) without requiring physical contact. The term “touch” as used herein should therefore be interpreted accordingly.
Further example applications of the present technique can be envisaged. For example, a touch sensor according to any of the examples described above could be used to implement or form part of a touch sensitive control panel for a personal computer or a mobile personal computer. An example of a mobile personal computer 120 or notebook PC is shown in
As shown in
d shows an example in which the touch sensitive pad 150 is implemented using a touch sensor according to the present technique. The user can control the movement of a pointer or cursor on the display screen 122, by applying a finger to a sensing surface of a PSE forming part of the touch sensitive pad 150. When a desired position is reached, the user can engage a particular function, which is identified on the display screen 122 corresponding to that reached position by pressing on the sensing surface to register a pressure event, which is detected by the PSD. Thus the user can navigate and select a function without having to lift the finger from the sensing surface.
Various aspects and features of the present invention are defined in the appended claims. Further aspects of the present invention may include a control panel comprising a position sensing element coupled to a position interface circuit operable to determine the position of an object applied to the position sensing element, and at least one pressure sensing device below the position sensing element, wherein the pressure sensing device responds to user pressure applied at multiple locations on the user-operable user surface. The control panel may also include one or more mechanical or touch sensitive switches disposed outside of the sensing surface of the position sensing element.
According to another aspect of the present invention there is provided a method of identifying one of a plurality of user indicated signals. The method starts with a process step of determining a position of an object (100) on a sensing surface of a position sensing element (60), then sensing pressure applied to a pressure sensing device in response to a displacement of the position sensing element caused by pressure being applied to the sensing surface of the position sensing element (60) by the object (100) at the determined location, and identifying one of the plurality of user indicated signals by correlating the position of the object on the sensing surface with the pressure detected by the pressure sensing device, after which the process terminates. The step of determining the position of the object (100) on the sensing surface of a position sensing element (60), includes determining whether the object is at one of a plurality of predetermined locations on the sensing surface, and the identifying the user indicated signal includes correlating the position of the object at one of the predetermined locations with the detected pressure, each of the predetermined location corresponding to one of the plurality of user indicated signals.
According to another aspect of the present invention there is provided a method of controlling a device in response to one of a plurality of user indicated signals, the method comprising:
determining a position of an object (100) on a sensing surface of a position sensing element (60),
sensing pressure applied to a pressure sensing device in response to a displacement of the position sensing element caused by pressure being applied to the sensing surface of the position sensing element (60) by the object (100) at the determined position,
identifying one of the plurality of user indicated signals by correlating the position of the object on the sensing surface with the pressure detected by the pressure sensing device, and
controlling the device in accordance with the user indicated signal.
Optionally, the method may also include generating on a display an visual indication representing the control of the device in accordance with the user indicated signal. The method may also include generating a haptic signal in response to the identifying the user indicated signal. In other examples, the method may include the determining the position of the object (100) on the sensing surface of a position sensing element (60), including determining whether the object is at one of a plurality of predetermined locations on the sensing surface, and the identifying the user indicated signal includes correlating the position of the object at one of the predetermined locations with the detected pressure, each of the predetermined locations corresponding to one of the plurality of user indicated signals.
Another aspect of the present invention provides an apparatus for controlling a device in response to one of a plurality of user indicated signals, the apparatus comprising means for determining a position of an object (100) on a sensing surface of a position sensing element (60),
means for sensing pressure applied to a pressure sensing device in response to a displacement of the position sensing element caused by pressure being applied to the sensing surface of the position sensing element (60) by the object (100) at the determined position,
means for identifying one of the plurality of user indicated signals by correlating the position of the object on the sensing surface with the pressure detected by the pressure sensing device, and
means for controlling the device in accordance with the user indicated signal.
Various modifications may be made to the embodiments of the invention hereinbefore described without departing from the scope of the present invention.
| Number | Date | Country | |
|---|---|---|---|
| 60889726 | Feb 2007 | US |
