Capacitive touch sensor button activation

TECHNICAL FIELD

0001Embodiments of the invention relate to the field of capacitive touch sensors and more specifically, but not exclusively, to capacitive touch sensor button activation.

BACKGROUND

0002Accidental key press is a concern when implementing a capacitive touch sensor in a keypad. A traditional search-and-press technique involves the user finding the desired key (usually visually), and then pressing the desired button to activate the button. Accidental key press is especially a problem when trying to physically locate the correct key to be selected. For example, when trying to dial a number on a phone keypad with the traditional search-and-press technique using only one hand, a person will typically place their thumb on the keypad, move their thumb to the correct key, and then press. With capacitive touch sensor keypads, moving the thumb over various keys results in multiple unwanted key presses.

BRIEF DESCRIPTION OF THE DRAWINGS

0003Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

0004<figref idref="DRAWINGS">FIG. 1</figref> is a diagram illustrating a search-and-tap capacitive touch sensor button activation technique in accordance with an embodiment of the invention.

0005<figref idref="DRAWINGS">FIG. 2</figref> is a flowchart illustrating the logic and operations of a search-and-tap capacitive touch sensor button activation technique in accordance with an embodiment of the invention.

0006<figref idref="DRAWINGS">FIG. 3</figref> is a diagram illustrating a search-and-lift capacitive touch sensor button activation technique in accordance with an embodiment of the invention.

0007<figref idref="DRAWINGS">FIG. 4</figref> is a flowchart illustrating the logic and operations of a search-and-lift capacitive touch sensor button activation technique in accordance with an embodiment of the invention.

0008<figref idref="DRAWINGS">FIG. 5A</figref> is a diagram illustrating a scroll wheel capacitive touch sensor in accordance with an embodiment of the invention.

0009<figref idref="DRAWINGS">FIG. 5B</figref> is a diagram illustrating a slider capacitive touch sensor in accordance with an embodiment of the invention.

0010<figref idref="DRAWINGS">FIG. 6</figref> is a diagram illustrating embodiments of a mobile device to utilize embodiments of capacitive touch sensor button activation as described herein.

DETAILED DESCRIPTION

0011In the following description, numerous specific details are set forth to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that embodiments of the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring understanding of this description.

0012Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

0013Embodiments of the invention include capacitive touch sensor button activation techniques to avoid accidental key presses. Such techniques include a search-and-tap technique and a search-and-lift-technique. These techniques enable a user to find and activate buttons without visual reference to the capacitive touch sensor.

0014Turning to <figref idref="DRAWINGS">FIG. 1</figref>, a capacitive touch sensor <b>100</b> is shown. <figref idref="DRAWINGS">FIG. 1</figref> shows a capacitive touch sensor <b>100</b> utilized as a keypad. In one embodiment, sensor <b>100</b> may be part of a mobile device, such as a mobile phone. Embodiments of a mobile device will discussed below in conjunction with <figref idref="DRAWINGS">FIG. 6</figref>. While embodiments herein are described in relation to a keypad, it will be understood that embodiments of the invention may be utilized with alternative capacitive touch sensor controls, such as a scroll wheel, slider, or the like. It will also be understood that the terms “key” and “button” are used herein interchangeably.

0015In one embodiment, capacitive touch sensor <b>100</b> is logically divided into keys <b>101</b>-<b>112</b>. In one embodiment, keys <b>101</b>-<b>112</b> may correspond to traditional phone keys, however, embodiments herein are not limited to phone keys.

0016A touch, such as by a finger, on capacitive touch sensor <b>100</b> is detected by embedded sensors and indicates where the user has touched sensor <b>100</b>. An X-Y position on sensor <b>100</b> where the touch is sensed is translated to a particular key.

0017In alternative embodiments, two or more capacitive touch sensors may be combined to form keys <b>101</b>-<b>112</b>. For example, keys <b>101</b>-<b>106</b> may be associated with one capacitive touch sensor and keys <b>107</b>-<b>112</b> may be associated with another sensor. Button activation logic <b>140</b> translates the X-Y positioning of a touch on one of the sensors to a particular key.

0018Sensor <b>100</b> may include an overlay (not shown) that includes physical keys associated with capacitive touch sensor keys <b>101</b>-<b>112</b>. In one embodiment, such physical keys may be printed with symbols to indicate to a user the positions of the keys. In another embodiment, the overlay may include physical locating elements, such as embossed keys or key outlines, to help the user locate the desired key without looking at the keypad. In another embodiment, a single key may have an associated physical locating element, such as a raised bump, to allow the user to know where their thumb/finger is on the keypad and dial the phone without looking at the keypad.

0019It will be understood that the term “touch” as used herein includes direct physical contact with sensor <b>100</b> and indirect physical contact with sensor <b>100</b>. In an example of indirect physical contact, one or more layers of material, such as a plastic key layer, may be placed on top of sensor <b>100</b> such that a user's finger makes direct physical contact with the plastic key layer and not directly with sensor <b>100</b>. However, in this case, a touch may still be detected by sensor <b>100</b>.

0020In one embodiment, capacitive touch sensor <b>100</b> includes CapSense™ technology as promulgated by the Cypress Semiconductor Corporation. CapSense™ may be used with Cypress's family of Programmable System-on-Chip™ (PSoC™) devices. PSoC devices include configurable mixed signal arrays.

0021Embodiments of the invention include a search-and-tap capacitive touch sensor button activation technique. These techniques may be implemented in a button activation logic <b>140</b> coupled to capacitive touch sensor <b>100</b>. Button activation logic <b>140</b> may include hardware, software, or any combination thereof.

0022In search-and-tap, the device user may put a finger in contact with the capacitive touch sensor and move their finger around the keypad to search for the desired key. Then, when the user wants to select the desired key, rather than pressing the key, the user lifts their finger and returns it to the same key. The key is “pressed” by lifting the finger and returning it to the same key instead of only pressing the finger down.

0023The touch sensor button activation logic <b>140</b> may allow the user to move their finger around to different keys without causing a key press to be registered. For example, moving from key A to key B to Key C, etc., would not result in any key being selected. However, a transition from key A to no key (i.e., a lift) and back to key A would result in key A being selected.

0024An example of search-and-tap is shown in <figref idref="DRAWINGS">FIG. 1</figref>. As shown at <b>150</b>, a solid circle represents a touch and an open circle represents a lift. A user's finger is placed on key <b>102</b> (shown at <b>120</b>). The user drags their finger across key <b>105</b> to key <b>108</b> (shown at <b>121</b>) maintaining contact with sensor <b>100</b>. The user then drags their finger to key <b>109</b> (shown at <b>122</b>) maintaining contact with sensor <b>100</b>. The user then lifts their finger (shown at <b>123</b>) and then touches key <b>109</b> a second time (as shown at <b>124</b>). The sensing of the second touch at key <b>109</b> initiates the activation of key <b>109</b>.

0025Turning to <figref idref="DRAWINGS">FIG. 2</figref>, a flowchart <b>200</b> of an embodiment of a search-and-tap technique is shown. Embodiments of flowchart <b>200</b> may be implemented as instructions executable by a processor on a mobile device having a capacitive touch sensor. The logic of flowchart <b>200</b> may be implemented as software, hardware, or any combination thereof.

0026Starting in a block <b>202</b>, a first touch is sensed by a capacitive touch sensor at a first button on the sensor. Proceeding to a block <b>204</b>, a lift is sensed at a second button on the sensor. A lift may include a sensed touch that ceases being detected. Continuing to a block <b>206</b>, a second touch is sensed at the second button. A drag may be sensed from the first button to the second button without activating any buttons on the capacitive touch sensor.

0027In one embodiment, the first and second buttons may be associated with the same button. For example, in <figref idref="DRAWINGS">FIG. 1</figref>, the user may touch key <b>101</b> (i.e., a first button), lift their finger, and return their finger to key <b>101</b> (i.e., a second button) to activate key <b>101</b>.

0028The logic then proceeds to decision block <b>208</b> to determine if the time between the first and second touches has exceeded a timeout threshold. If the timeout threshold has not been exceeded, then the logic proceeds to a block <b>210</b> to activate the second button in response to the second touch.

0029If the timeout threshold has been exceeded, then the logic proceeds to a block <b>212</b> to disregard the second touch as a button activation. In this instance, the user's finger has been off of the sensor for too long between the first and second touches. This second touch may be interpreted as a first touch, as shown in block <b>214</b>. After block <b>214</b>, the logic returns to block to block <b>204</b> when a lift is sensed.

0030Turning to <figref idref="DRAWINGS">FIG. 3</figref>, capacitive touch sensor <b>100</b> utilizing an embodiment of a search-and-lift capacitive touch sensor button activation technique is shown. In one embodiment, search-and-lift defines a key press as key A to no key. This technique has the similar effect as the traditional search-and-press; the process of tapping the key results in that key being selected once. The search-and-lift technique may work equally well with holding the device with one hand and dragging the thumb around (one-handed technique) or with holding the device with one hand and typing with the other hand (two-handed technique).

0031An example of search-and-lift is shown in <figref idref="DRAWINGS">FIG. 3</figref>. A user places their finger on key <b>102</b> (shown at <b>320</b>). The user drags their finger across key <b>105</b> to key <b>108</b> (shown at <b>321</b>) maintaining contact with sensor <b>100</b>. The user then drags their finger from key <b>108</b> to key <b>109</b> (shown at <b>322</b>) maintaining contact with sensor <b>100</b>. The user then lifts their finger off of sensor <b>100</b> (as shown at <b>323</b>). The lift (i.e., the absence of sensed touch on sensor <b>100</b>) from sensor <b>100</b> at key <b>109</b> activates key <b>109</b>.

0032Turning to <figref idref="DRAWINGS">FIG. 4</figref>, a flowchart <b>400</b> of an embodiment of a search-and-lift technique is shown. Embodiments of flowchart <b>400</b> may be implemented as instructions executable by a processor on a mobile device having a capacitive touch sensor. The logic of flowchart <b>400</b> may be implemented as software, hardware, or any combination thereof.

0033Starting in a block <b>402</b>, a touch is sensed at a first button on a capacitive touch sensor. Proceeding to a block <b>404</b>, a lift is sensed at a second button on the sensor. Continuing to a block <b>406</b>, the second button is activated in response to the lift. A drag may be sensed from the first button to the second button without activating any buttons on the capacitive touch sensor.

0034In one embodiment, the first and second buttons may be the same button. For example, the user may place their finger on key <b>101</b> and lift their finger from key <b>101</b> resulting in the activation of key <b>101</b>.

0035From the user's perspective, the search-and-lift technique has the feel of traditional search-and-press. However, the user may also drag their finger around the keypad without activating any keys until their finger is lifted. This enables a user to “feel around” the keypad for the desired key without looking at the keypad as well as preventing any unwanted key presses. The user may identify the location of their finger on the keypad without looking at the keypad by using physical locating elements as discussed above.

0036Turning to <figref idref="DRAWINGS">FIG. 5A</figref>, an embodiment of a capacitive touch sensor scroll wheel <b>500</b> coupled to button activation logic <b>140</b> is shown. Scroll wheel <b>500</b> is logically divided into buttons <b>501</b>-<b>507</b>. Scroll wheel <b>500</b> may utilize a search-and-tap or a search-and-lift technique as directed by button activation logic <b>140</b>. Scroll wheel <b>500</b> is not limited to the button arrangement shown in <figref idref="DRAWINGS">FIG. 5</figref>. Scroll wheel <b>500</b> may use an X-Y matrix to determine a button associated with a particular touch position or area.

0037<figref idref="DRAWINGS">FIG. 5B</figref> shows an embodiment of a capacitive touch sensor slider <b>550</b> coupled to button activation logic <b>140</b>. Slider <b>550</b> is logically divided into buttons <b>551</b>-<b>557</b>. In one embodiment, slider <b>550</b> may be used for linear control applications, such as a volume control, a speed control, such as on a treadmill, or the like.

0038Embodiments of the invention provide for use of a capacitive touch sensor without having to visually reference the buttons of the sensor. Embodiments herein allow a user to avoid accidental key presses, such as when dialing a mobile phone with one hand. Button activation techniques described herein may be applied to a variety of capacitive touch sensor applications, such as keypads, scroll wheels, and slider controls.

0039<figref idref="DRAWINGS">FIG. 6</figref> illustrates embodiments of a mobile device <b>600</b> on which embodiments of the present invention may be implemented. Mobile device <b>600</b> includes a processor <b>602</b> and a memory <b>604</b> coupled to a bus <b>608</b>. Mass storage <b>612</b>, Non-Volatile Storage (NVS) <b>606</b>, network interface (I/F) <b>614</b>, capacitive touch sensor <b>618</b>, and display <b>620</b> may also be coupled to bus <b>608</b>. Embodiments of mobile device <b>600</b> include, but are not limited to, a mobile phone, a media player, a personal digital assistant, a pocket personal computer (PC), a notebook computer, or the like.

0040In one embodiment, mobile device <b>600</b> includes processor <b>602</b> coupled to memory <b>604</b> and NVS <b>606</b>. Processor <b>602</b> may execute instructions loaded into memory <b>604</b> from NVS <b>606</b>. In one embodiment, button activation instructions <b>607</b> for one or more button activation techniques as described herein are stored in NVS <b>606</b> for use with capacitive touch sensor <b>618</b>. In one embodiment, mobile device <b>600</b> may include menu options for the user to select the desired button activation technique including search-and-tap and search-and-lift.

0041Memory <b>604</b> may include, but is not limited to, Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Synchronized Dynamic Random Access Memory (SDRAM), or the like. In one embodiment, memory <b>604</b> may include one or more memory units that do not have to be refreshed.

0042Components of mobile device <b>600</b> may be connected by various interconnects, such as bus <b>608</b>. In one embodiment, an interconnect may be point-to-point between two components, while in other embodiments, an interconnect may connect more than two components.

0043Mobile device <b>600</b> may interface to external systems through network interface <b>614</b> using a wired connection, a wireless connection, or any combination thereof. Network interface <b>614</b> may include, but is not limited to, a modem, a Network Interface Card (NIC), or the like. Network interface <b>614</b> may include a wireless communication module. The wireless communication module may employ a Wireless Application Protocol to establish a wireless communication channel. The wireless communication module may implement a wireless networking standard.

0044A carrier wave signal <b>622</b> may be received/transmitted by network interface <b>614</b>. In the embodiment illustrated in <figref idref="DRAWINGS">FIG. 6</figref>, carrier wave signal <b>622</b> is used to interface mobile device <b>600</b> with a network <b>624</b>, such as a Local Area Network (LAN), a Wide Area Network (WAN), a mobile phone telecommunications network, or the like. In one embodiment, network <b>624</b> is further coupled to a processing system <b>626</b> such that mobile device <b>600</b> and processing system <b>626</b> may communicate over network <b>624</b>. Processing system <b>626</b> may include a mobile device, such as a mobile phone, a computer system, or the like.

0045Mobile device <b>600</b> may include non-volatile storage <b>606</b> on which firmware may be stored. Non-volatile storage devices include, but are not limited to, Read-Only Memory (ROM), Flash memory, Erasable Programmable Read Only Memory (EPROM), Electronically Erasable Programmable Read Only Memory (EEPROM), Non-Volatile Random Access Memory (NVRAM), or the like.

0046Mass storage <b>612</b> includes, but is not limited to, a magnetic disk drive, such as a hard disk drive, an optical disk drive, or the like. It is appreciated that instructions executable by processor <b>602</b> may reside in mass storage <b>612</b>, memory <b>604</b>, non-volatile storage <b>606</b>, or may be transmitted or received via network interface <b>614</b>.

0047In one embodiment, mobile device <b>600</b> may execute an Operating System (OS). Embodiments of an OS include a Microsoft Windows® operating system, an Apple® operating system, or the like. In one embodiment, instructions for executing an OS may be stored on mass storage <b>612</b>.

0048For the purposes of the specification, a machine-readable medium includes any mechanism that provides (i.e., stores and/or transmits) information in a form readable or accessible by a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device with a set of one or more processors, etc.). For example, a machine-readable medium includes, but is not limited to, recordable/non-recordable media (e.g., Read-Only Memory (ROM), Random Access Memory (RAM), magnetic disk storage media, optical storage media, a flash memory device, etc.). In addition, a machine-readable medium may include propagated signals such as electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.).

0049Various operations of embodiments of the present invention are described herein. These operations may be implemented using hardware, software, or any combination thereof. These operations may be implemented by a machine using a processor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or the like. In one embodiment, one or more of the operations described may constitute instructions stored on a machine-readable medium, that if executed by a machine, will cause the machine to perform the operations described. The order in which some or all of the operations are described should not be construed as to imply that these operations are necessarily order dependent. Alternative ordering will be appreciated by one skilled in the art having the benefit of this description. Further, it will be understood that not all operations are necessarily present in each embodiment of the invention.

0050The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible, as those skilled in the relevant art will recognize. These modifications can be made to embodiments of the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the following claims are to be construed in accordance with established doctrines of claim interpretation.