Patent Publication Number: US-9423500-B2

Title: Electronic device with gesture detection system and methods for using the gesture detection system

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/098,884, filed Dec. 6, 2013, which claims the benefit of U.S. Provisional Application No. 61/976,691, filed Sep. 11, 2013, each of which is hereby incorporated by reference herein its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to electronic devices having gesture detection systems and, more particularly, to electronic devices with infrared light emitting diode gesture detection system and methods for using the gesture detection system. 
     BACKGROUND 
     Mobile devices such as cellular telephones, smart phones, and other handheld or portable electronic devices such as personal digital assistants (“PDAs”), headsets, MP3 players, etc. have become popular and ubiquitous. As more and more features have been added to mobile devices, there has been an increasing desire to equip these mobile devices with input/output mechanisms that accommodate numerous user commands and/or react to numerous user behaviors. It is of increasing interest that mobile devices be capable of detecting the presence of, and determining with some accuracy the position of, physical objects located outside of the mobile devices and, more particularly, the presence and location of human beings (or portions of their bodies, such as their heads or hands) who are using the mobile devices or otherwise are located nearby the mobile devices. By virtue of such capabilities, the mobile devices are able to adjust their behavior in a variety of manners that are appropriate given the presence (or absence) and location of the human beings and/or other physical objects. 
     While remote sensing devices such as infrared (or, more accurately, near-infrared) transceivers have been employed in the past in some mobile devices to allow for the detection of the presence and/or location of human beings and/or physical objects even when not in physical contact with the mobile devices, such sensing devices have been limited in various respects. In particular, some such near-infrared transceivers in some such mobile devices are only able to detect the presence or absence of a human being/physical object within a certain distance from the given transceiver (e.g., binarily detect that the human being/physical object is within a predetermined distance or proximity to the transceiver), but not able to detect the three-dimensional location of the human being/physical object in three-dimensional space relative to the transceiver. Also, some such transceivers in some such mobile devices are undesirably complicated or require large numbers of components in order to operate, which in turn renders such devices unduly expensive. Many such implementations are modular in type and thus require user to have prior knowledge of the module location in order to operate above the module, resulting in a less than optimum experience. Further, those systems are focused on a specific implementation of gesturing and not designed to be used as part of other systems such as side approach detection, eye tracking, facial illumination, and data transmissions. 
    
    
     
       DRAWINGS 
       While the appended claims set forth the features of the present techniques with particularity, these techniques may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a perspective view of an electronic device, which is depicted as a mobile device in the drawing. 
         FIG. 2  shows example components of the electronic device of  FIG. 1 . 
         FIG. 3A  is a top view of the electronic device of  FIG. 1 . 
         FIG. 3B  is another top view of the electronic device of  FIG. 1 . 
         FIGS. 4-12  show steps that may be carried out according to various embodiments. 
     
    
    
     DESCRIPTION 
     The present disclosure sets forth an electronic device with an infrared (“IR”) light emitting diode (“LED”) gesture detection system and methods for using the gesture detection system. Various embodiments of the distributed IR LED gesture detection system offer users a better experience because the gesture detection system is designed to mimic and/or exceed touch screen coverage area but is not in contact with the cover glass. Another benefit for this distributed IR LED detection system is the ability to enhance hand approach detection, where the device may detect a user&#39;s hand approaching from any side of the device. The enhanced hand approach detection may be used to wake up device. In addition, the IR LED gesture detection system is not only capable of detecting gestures, but also supports other functionalities. As discussed in more detail below, the IR LED gesture detection system may also support hand approach detection, eye movement tracking, facial illumination, and IR proximity functionality to disable a touch screen of the device during phone calls. Accordingly, the IR LED gesture detection system provides the benefit of additional applications and functionalities to a device employing such gesture detection system. 
     In an embodiment, an electronic device includes LEDs disposed proximate to the perimeter of the device and a sensor disposed in the device. The LEDs project IR light. The sensor detects IR light originating from at least one of the LEDs reflected from off of a person. Based on the relative strength of the detected IR light, the device carries out a function based on the detected IR light from two selected LEDs. The device may detect a gesture using at least two of the LEDs (i.e., the active LEDs). 
     The device may identify, based on the relative strength of the detected IR light, at least one LED having much weaker detected IR light. The device may ignore that LED or LEDs. In another embodiment, the device may ignore at least one LED whose projected IR light is not detected by the sensor (e.g., due to blockage by a person&#39;s hand). 
     In another embodiment, if the detected IR light originating from one LEDs becomes weaker than the detected IR light of at least one of the remaining LEDs, the device may reselect at least two other LEDs. After reselection, the device may carry out a function based on detected IR light from the two reselected LEDs. The two reselected LEDs may include the other of the two selected LEDs having the stronger detected IR light. This embodiment is directed to using subgroups of the plurality of LEDs, and dynamically switching between the LED subgroups, to detect gestures. 
     In a further embodiment, the device illuminates the person&#39;s face with one or more LEDs for more diffused type or broad illumination (i.e., a facial illumination function). The LED (or LEDs) projects IR light onto the person&#39;s face, and the sensor receives IR light reflected off of the person&#39;s face. Based on a characteristic of the received IR light, the device determines the uniformity of the facial illumination. Based on the determined uniformity, the device may increase or decrease the projection of the LED (or LEDs). 
     The characteristic of the received IR light may include the relative strength of the received IR light. Based on the relative strength of the received IR light, the device may further determine a difference between the received IR light from the LED having the stronger reflected IR light and the LED having the weaker reflected IR light. Based on the determined difference, the device may increase the IR light projection of the LED having the weaker reflected IR light. This embodiment is directed to an IR transceiver (LED and sensor) closed loop system, which may be used to enhance the facial illumination function. The IR transceiver closed loop system adaptively adjusts the LEDs&#39; IR light projections and coverage based on the received IR light signal to provide a more uniform illumination of a person&#39;s face. 
     In yet another embodiment, an electronic device includes LEDs disposed proximate to the perimeter of the device and a sensor disposed in the device. The LEDs project IR light. The sensor detects IR light originating from at least one of the LEDs reflected from off of a person. Based on the detected IR light, the device detects the presence of the person. If the presence of the person is detected, the device carries out a function. 
     In an embodiment, the LEDs sequentially project IR light. If the presence of the person is detected, the device may turn on a screen, wake up the electronic device, display the time, initiate a notification, change a user interface, or reduce power consumption. The sensor detects IR light originating from at least two of the LEDs reflected from off of the person and use the reflected light to detect a gesture. 
     In another embodiment, the LEDs simultaneously project IR light to detect a person from a longer range. 
     In an embodiment, the electronic device includes a first group of LEDs that are proximate to the perimeter of the device, a second group of LEDs proximate to the perimeter of the device, and a sensor in the device. The first group of LEDs and the second group of LEDs project IR light. The sensor then detects IR light reflected off of a person. The device then generates signals based on the detected IR light. If the detected IR light originates from any of the LEDs of the first group, the device processes the signals as a single, first LED. If the detected IR light originates from any of the LEDs of the second group, the device processes the signals as a single, second LED. Based on whether the signals are processed as the first LED or the second LED, the device determines whether the person is making a first gesture or a second gesture. 
     In another embodiment, an electronic device first detects its orientation. Based on the detected orientation, the device activates two of the LEDs or a subgroup of the LEDs (the subgroup may have two or more LEDs), which are disposed proximate to the perimeter of the device. A sensor disposed in the device detects reflected IR light originating from at least one of the two activated LEDs. Based on the detected IR light, the device carries out a function. 
     If the orientation of the device is detected to be a portrait mode, the device activates a first set of two LEDs. If the orientation of the device is detected to be a landscape mode, the device then activates a second set of two LED. 
     If the orientation of the electronic device is detected to be a portrait mode, both LEDs in the first set of two LEDs may simultaneously project IR light. If the orientation of the electronic device is detected to be a landscape mode, both LEDs in the second set of two LEDs may simultaneously project IR light. 
     In still another embodiment, an electronic device includes a first LED disposed proximate to the perimeter of the device, a second LED disposed proximate to the perimeter of the device, and a sensor disposed closer to the first LED than the second LED. The first LED projects IR light, and the second LED projects IR light. The sensor detects reflected IR light from off of a person from both LEDs. The first LED (disposed closer to the sensor) allows detection down to glass (e.g., detect a person touching the glass). The second LED (disposed further to the sensor) is expected to cover a range before the person touches the glass. Based on the detected IR light, the device carries out a voting function and determines whether to deactivate a touch screen of the device based on the results of the voting function. 
     To determine whether to deactivate the touch screen, if the detected IR light originates from the second LED, the device may detect that the person is approaching the device. If the detected IR light originates from the first LED, the device may deactivate the touch screen. In an embodiment, the second LED may have a longer range than the first LED. 
     In a further embodiment, an electronic device includes a first LED disposed proximate to the perimeter of the electronic device, a second LED disposed proximate to the perimeter of the device, and a camera. The first LED projects IR light onto a person&#39;s eye, and the second LED projects IR light onto the person&#39;s eye. The camera captures IR light spots from the first LED and the second LED on the person&#39;s eye. The device then tracks the captured IR light spots to detect movement of the eye. 
     The device may include at least four LEDs disposed proximate to the perimeter of the device. Then device may determine which group of two LEDs is the most appropriate for tracking movement of the eye. The device may identify an LED that is weaker than the remaining LEDs. The device may then energize the identified LED via the IR transceiver (LED and sensor) closed loop system described above with respect to the facial illumination function. 
     The device may further determine a characteristic of the captured IR light spots. The characteristic of the captured IR light spot may include the strength of the captured IR light spots to determine the location of the person&#39;s head relative to the device. The characteristic may also include the angle at which the captured IR light spots are received. The characteristic may further include the direction from which the captured IR light spots are received. 
       FIG. 1  is a perspective view of an electronic device  100  (also referred to as “device  100 ” or “device”) according to an embodiment, which is depicted as a mobile device in the drawing. The electronic device  100  includes a housing  110 , LEDs disposed proximate to the perimeter of the housing, and a sensor  130 . The housing  110  includes a cover glass and an opening  112  formed therein, and a speaker is disposed in the housing below the opening  112 . In the embodiment shown, the LEDs include a first LED  120 , a second LED  122 , a third LED  124 , and a fourth LED  126 . As shown in  FIG. 1 , the first LED  120 , the second LED  122 , the third LED  124 , and the fourth LED  126  are disposed proximate to the four corners of the housing  110 , respectively. 
     Although  FIG. 1  illustrates the housing  110  as having a substantially rectangular shape including sides and rounded corners, in other embodiments, the housing  110  may have another shape without sides and/or corners. Furthermore, while  FIG. 1  shows four LEDs located proximate to the corners of the electronic device  100 , in other embodiments, the LEDs may be disposed proximate to other areas of the perimeter of the device  100 , instead of the corners of the device  100 . 
     Each of the LEDs projects or emits IR light having a wavelength that typically ranges from about 850 nanometers to about 1 micrometer for infrared. The LEDs could project light having a wavelength that ranges lower into the visible region as well, e.g., down toward 400 nm range. The sensor  130 , which is an IR light sensor or receiver, detects IR light from the LEDs. 
     In one embodiment, the LEDs are of the same color. The LEDs may project or emit IR light sequentially, or the LEDs may project or emit light following a pulse or wave-shaped pattern. In another embodiment, the LEDs are of different colors, and may project or emit light simultaneously. 
     In the embodiment shown in  FIG. 1 , The LEDs are equipped with microfilm beam bending lenses to direct the IR light beams projected by the LEDs in certain directions. The sensor  130  is disposed proximate to the opening  112  (i.e., proximate to the speaker). The sensor  130  is also be disposed closer to the first LED  120  than to the remaining three LEDs to perform an IR proximity function, which will be described in detail below. 
       FIG. 2  shows internal components of the device  100  of  FIG. 1 , in accordance with an embodiment of the disclosure. As shown in  FIG. 2 , the internal components  200  include one or more wireless transceivers  202 , a processor  204  (e.g., a microprocessor, microcomputer, application-specific integrated circuit, etc.), a memory portion  206 , one or more output devices  208 , and one or more input devices  210 . The internal components  200  can further include a component interface  212  to provide a direct connection to auxiliary components or accessories for additional or enhanced functionality. The internal components  200  may also include a power supply  214 , such as a battery, for providing power to the other internal components while enabling the mobile device to be portable. Further, the internal components  200  additionally include one or more sensors  228 . All of the internal components  200  can be coupled to one another, and in communication with one another, by way of one or more internal communication links  232  (e.g., an internal bus). 
     Further, in the embodiment of  FIG. 2 , the wireless transceivers  202  particularly include a cellular transceiver  203  and a Wi-Fi transceiver  205 . More particularly, the cellular transceiver  203  is configured to conduct cellular communications, such as 3G, 4G, 4G-LTE, vis-à-vis cell towers (not shown), albeit in other embodiments, the cellular transceiver  203  can be configured to utilize any of a variety of other cellular-based communication technologies such as analog communications (using AMPS), digital communications (using CDMA, TDMA, GSM, iDEN, GPRS, EDGE, etc.), and/or next generation communications (using UMTS, WCDMA, LTE, IEEE 802.16, etc.) or variants thereof. 
     By contrast, the Wi-Fi transceiver  205  is a wireless local area network (WLAN) transceiver  205  configured to conduct Wi-Fi communications in accordance with the IEEE 802.11 (a, b, g, or n) standard with access points. In other embodiments, the Wi-Fi transceiver  205  can instead (or additionally) conduct other types of communications commonly understood as being encompassed within Wi-Fi communications, such as some types of peer-to-peer (e.g., Wi-Fi Peer-to-Peer) communications. Further, in other embodiments, the Wi-Fi transceiver  205  can be replaced or supplemented with one or more other wireless transceivers configured for non-cellular wireless communications including, for example, wireless transceivers employing ad hoc communication technologies such as HomeRF (radio frequency), Home Node B (3G femtocell), Bluetooth and/or other wireless communication technologies such as infrared technology. 
     Although in the embodiment shown in  FIG. 1 , the device  100  has two of the wireless transceivers  202  (that is, the transceivers  203  and  205 ), the present disclosure is intended to encompass numerous embodiments in which any arbitrary number of wireless transceivers employing any arbitrary number of communication technologies are present. By virtue of the use of the wireless transceivers  202 , the device  100  is capable of communicating with any of a variety of other devices or systems (not shown) including, for example, other mobile devices, web servers, cell towers, access points, other remote devices, etc. Depending upon the embodiment or circumstance, wireless communication between the device  100  and any arbitrary number of other devices or systems can be achieved. 
     Operation of the wireless transceivers  202  in conjunction with others of the internal components  200  of the device  100  can take a variety of forms. For example, operation of the wireless transceivers  202  can proceed in a manner in which, upon reception of wireless signals, the internal components  200  detect communication signals and the transceivers  202  demodulate the communication signals to recover incoming information, such as voice and/or data, transmitted by the wireless signals. After receiving the incoming information from the transceivers  202 , the processor  204  formats the incoming information for the one or more output devices  208 . Likewise, for transmission of wireless signals, the processor  204  formats outgoing information, which can but need not be activated by the input devices  210 , and conveys the outgoing information to one or more of the wireless transceivers  202  for modulation so as to provide modulated communication signals to be transmitted. 
     Depending upon the embodiment, the input and output devices  208 ,  210  of the internal components  200  can include a variety of visual, audio and/or mechanical outputs. For example, the output device(s)  208  can include one or more visual output devices  216  such as a liquid crystal display and/or light emitting diode indicator, one or more audio output devices  218  such as a speaker, alarm, and/or buzzer, and/or one or more mechanical output devices  220  such as a vibrating mechanism. The visual output devices  216  among other things can also include a video screen. Likewise, by example, the input device(s)  210  can include one or more visual input devices  222  such as an optical sensor (for example, a camera lens and photosensor), one or more audio input devices  224  (or further for example a microphone of a Bluetooth headset), and/or one or more mechanical input devices  226  such as a flip sensor, keyboard, keypad, selection button, navigation cluster, touch pad, capacitive sensor, motion sensor, and/or switch. Operations that can actuate one or more of the input devices  210  can include not only the physical pressing/actuation of buttons or other actuators, but can also include, for example, opening the mobile device, unlocking the device, moving the device to actuate a motion, moving the device to actuate a location positioning system, and operating the device. 
     As mentioned above, the internal components  200  also can include one or more of various types of sensors  228  as well as a sensor hub to manage one or more functions of the sensors. The sensors  228  may include, for example, proximity sensors (e.g., a light detecting sensor, an ultrasound transceiver or an infrared transceiver), touch sensors, altitude sensors, and one or more location circuits/components that can include, for example, a Global Positioning System (GPS) receiver, a triangulation receiver, an accelerometer, a tilt sensor, a gyroscope, or any other information collecting device that can identify a current location or user-device interface (carry mode) of the device  100 . Although the sensors  228  for the purposes of  FIG. 2  are considered to be distinct from the input devices  210 , in other embodiments it is possible that one or more of the input devices can also be considered to constitute one or more of the sensors (and vice-versa). Additionally, although in the present embodiment the input devices  210  are shown to be distinct from the output devices  208 , it should be recognized that in some embodiments one or more devices serve both as input device(s) and output device(s). In particular, if the device  100  includes a touch screen display, the touch screen display can be considered to constitute both a visual output device and a mechanical input device. 
     The memory portion  206  of the internal components  200  can encompass one or more memory devices of any of a variety of forms (e.g., read-only memory, random access memory, static random access memory, dynamic random access memory, etc.), and can be used by the processor  204  to store and retrieve data. In some embodiments, the memory portion  206  can be integrated with the processor  204  in a single device (e.g., a processing device including memory or processor-in-memory (PIM)), albeit such a single device will still typically have distinct portions/sections that perform the different processing and memory functions and that can be considered separate devices. In some alternate embodiments, the memory portion  206  of the device  100  can be supplemented or replaced by other memory portion(s) located elsewhere apart from the mobile device and, in such embodiments, the mobile device can be in communication with or access such other memory device(s) by way of any of various communications techniques, for example, wireless communications afforded by the wireless transceivers  202 , or connections via the component interface  212 . 
     The data that is stored by the memory portion  206  can include, but need not be limited to, operating systems, programs (applications), modules, and informational data. Each operating system includes executable code that controls basic functions of the device  100 , such as interaction among the various components included among the internal components  200 , communication with external devices via the wireless transceivers  202  and/or the component interface  212 , and storage and retrieval of programs and data, to and from the memory portion  206 . As for programs, each program includes executable code that utilizes an operating system to provide more specific functionality, such as file system service and handling of protected and unprotected data stored in the memory portion  206 . Such programs can include, among other things, programming for enabling the device  100  to perform a process such as the process for gesture recognition and discussed further below. Finally, with respect to informational data, this is non-executable code or information that can be referenced and/or manipulated by an operating system or program for performing functions of the device  100 . 
     Referring to  FIG. 1 , the first LED  120 , the second LED  122 , the third LED  124 , the fourth LED  126 , and the sensor  130  together form an IR gesture detection system. In an embodiment, each of the plurality of LEDs projects IR light, and the sensor  130  detects IR light reflected by a person or an object. Based on the reflected IR light, the device  100  selects at least two of the LEDs to detect gesture. In one embodiment, the device  100  selects two LEDs (e.g., the first LED  120  and the second LED  122 ) to detect a two-dimensional (“2D”) gesture. In another embodiment, the device  100  selects three LEDs (e.g., the first LED  120 , the second LED  122 , and the third LED  124 ) to detect a three-dimensional (“3D”) gesture. 
     In one embodiment, the device  100  requires no more than three LEDs to detect gestures. Thus, if the reflected IR light from one of the plurality of LEDs is weaker than the remaining LEDs (e.g., the first LED  120  is blocked by a person&#39;s hand), the device  100  may select two or three of the remaining LEDs for gesture detection (e.g., the second LED  122 , the third LED  124 , and the fourth LED  126 ). In other words, the device  100  may ignore the LED having the weakest reflected IR light. Based on the reflected IR light received by the sensor  130 , the device  100  may thus adaptively select the LEDs to be used for gesture detection as the person uses or grabs the device  100 . 
     In yet another embodiment, the device  100  may detect a person approaching the device  100 , e.g., the presence of the person near the device  100 . In this embodiment, the plurality of LEDS project IR light. The sensor  130  detects IR light originating from at least one of the plurality of LEDs (e.g., the first LED  120 ) reflected from off of the person. Based on the detected IR light from LED or LEDs, the device  100  detects whether the person is present and where the person is located with respect to the device  100  (e.g., direction and distance of the person with respect to the device  100 ). If the presence of the person is detected, the device  100  may carry out a function, e.g., turning on a screen, waking up the electronic device, displaying the time, initiating a notification, changing a user interface, and reducing power consumption. 
     In this embodiment, the plurality of LEDs project IR light pulses sequentially or serially. By cycling through the plurality of LEDs, the sensor  130  may detect any disturbance (e.g., a person&#39;s hand reflecting IR light projected by at least one of the LEDs) to indicate the person&#39;s hand approach. In response to the person&#39;s hand approach, the device  100  may turn on its display, initiate notification, or alert the person of messages. 
     In another embodiment, the plurality of LEDs or subset of them may project IR light simultaneously. This configuration increases the range or coverage of the plurality of LEDs and thus enhances hand approach detection. 
     In still another embodiment, the device  100  may cycle the plurality of LEDs for person or object detection, perform gesture detection, and enhanced hand approach detection. First, the plurality of LEDs projects IR light pulses serially, and the sensor  130  detects reflected IR light from any LED to detect a person or object. If the sensor  130  detects reflected IR light from only one LEDs or any combination of LEDs, the sensor  130  detects the presence of the person or object. Then, the plurality of LEDs project IR light pulses serially to detect gestures, and the sensor  130  detects reflected IR light from at least two of the LEDs. Next, some of the plurality of LEDs transmits IR light pulses simultaneously for enhanced hand approach detection. The LEDs are then turned off for a preset period of time (e.g., 20 milliseconds). The cycle may then be repeated. In this embodiment, the duration of the projected IR pulses is about 10 microseconds. In other embodiments, however, the duration of the projected IR pulses may vary. 
       FIG. 3A  is a top view of the electronic device of  FIG. 1 . In an embodiment, the device  100  includes an accelerometer to detect an orientation of the device  100 . Based on the orientation of the device  100 , i.e., portrait mode or landscape mode, the plurality of LEDs may be grouped into two or more independent gesture detection systems. 
     As shown in  FIG. 3A , the device  100  is in portrait mode. If the detected orientation of the device  100  is portrait mode, the first LED  120  and the second LED  122  may form into a first group  310 , and the third LED  124  and the fourth LED  126  may form into a second group  320 . Each of the first group  310  and the second group  320  functions as an independent 2D gesture detection system. If a person conducts a 2D gesture (e.g., swiping motion from left to right without moving toward or away from the device  100 ) near the top portion of the device  100 , the first group  310  will detect the gesture. If the person conducts a 2D gesture near the bottom portion of the device  100 , the second group  320  will detect the gesture. 
     If the detected orientation of the device is landscape mode (e.g., the device  100  shown in  FIG. 3A  rotated 90° in the clockwise or counterclockwise direction), the second LED  122  and the fourth LED  126  may form into a third group  330 , and the first LED  120  and the third LED  124  may form into a fourth group  340 . Each of the third group  330  and the fourth group  340  functions as an independent 2D gesture detection system. If a person conducts a 2D gesture near the top portion of the device  100  in landscape mode (e.g., the right portion of the device  100  as shown in  FIG. 3A ), the third group  330  will detect the gesture. If the person conducts a 2D gesture near the bottom portion of the device  100  in landscape mode (e.g., the left portion of the device  100  as shown in  FIG. 3A ), the fourth group  340  will detect the gesture. 
       FIG. 3B  is another top view of the electronic device of  FIG. 1 , according to an embodiment, in which the detected orientation of the device  100  is landscape mode. The device  100  includes two LED groups; the first group  310  includes the first LED  120  and the second LED  122 , and the second group  320  includes the third LED  124  and the fourth LED  126 . Unlike the system illustrated in  FIG. 3A , the first group  310  and the second group  320  do not function as two independent 2D gesture detection systems. Instead, the two LEDs in each group function as a single LED. In other words, the first LED  120  and the second LED  122  of the first group  310  functions as a single LED; the third LED  124  and the fourth LED  126  of the second group  320  function as another signal LED. Together, the first group  310  and the second group  320  constitute a single 2D gesture detection system. For example, when a person conducts a 2D gesture (e.g., swiping motion from left to right), the person&#39;s hand must reflect IR light projected by each of the first group  310  and the second group  320  in order to be detected by the sensor  130 . 
     In an embodiment, although the LEDs projects IR light sequentially, the sensor  130  interprets the signals from the LEDs of the first group together and interprets the signals from the LEDs of the second group together. In another embodiment, the LEDs in each group project IR light simultaneously (e.g., the first LED  120  and the second LED  120  project simultaneously, and the third LED  124  and the fourth LED  126  project simultaneously). In the simultaneously projection embodiment, IR light projected by the LEDs in each group is not distinguished, and light from all of the LEDs is treated as the same light, having double the optical output power. 
     While  FIGS. 3A and 3B  illustrate two LEDs in each group, in other embodiments, each group of LEDs includes three LEDs to detect 3D gestures. Furthermore, although  FIG. 3B  only shows the first group  310  and the second group  320 , in other embodiments, the third group  330  and the fourth group  340  (as shown in  FIG. 3B ) constitute a single 2D gesture detection system. 
       FIGS. 4-12  show steps that are carried out by the electronic device  100  according to various embodiments. 
     Referring to  FIG. 4 , a procedure  400  for gesture detection is carried out by the electronic device  100 . At step  402 , the electronic device  100  projects IR light from the LEDs (e.g., the first LED  120 , the second LED  122 , the third LED  124 , and the fourth LED  126 ). At step  404 , the sensor  130  of the device  100  detects IR light originating from at least two of the LEDs reflected from off of a person. At step  406 , the device  100  determines the relative strength, from among the LEDs, of the detected IR light. Then, at step  408 , the device  100  carries out a function based on the determined relative strength of the detected IR light. 
     In an embodiment, at step  408 , the device  100  may detect a gesture using the light from all of the LEDs. In another embodiment, at step  408 , the device  100  may ignore the LEDs whose light have not been detected by the sensor  130  (e.g., the LEDs may be blocked by a person&#39;s hand). Using the relative strength of the detected IR light, the device  100  may identify the LEDs having the weaker reflected IR light. The weakly received light information may be helpful, as it may serve as an additional data point when the device  100  is performing various functions (e.g., identifying the LEDs having the weaker reflected IR light may allow the device  100  to further determine a location of an object or person with respect to the device). In other embodiments, the device  100  may ignore the LEDs having the weaker reflected IR light. 
     In yet another embodiment, the device  100  selects three LEDs instead of two LEDs for 3D gesture detection. Then, using the three selected LEDs, the device  100  may detect a 3D gesture. 
     Referring to  FIG. 5 , a procedure  500  for reselecting IR LEDs is carried out by the electronic device  100 . At step  502 , the electronic device  100  projects IR light from the LEDs. At step  504 , the sensor  130  of the device  100  detects IR light reflected from off of a person. At step  506 , the device  100  selects, based on relative strength of the detected IR light, at least two of the LEDs having the stronger reflected IR light. Then, at step  508 , the device  100  carries out a function based on the detected IR light from the selected LEDs. 
     Next, at step  510 , the device  100  determines whether the detected IR light originating from one of the selected LEDs has become weaker than the detected IR light of at least one of the remaining LEDs (e.g., whether one of the two selected LEDs is blocked by the person&#39;s hand while the person is handling the device  100 ). If the device  100  determines that the detected IR light originating from one of the selected LEDs has not become weaker than the remaining LEDs (NO of step  510 ), the procedure returns to step  508  where the device  100  carries out a function based on the detected IR light from the selected LEDs. 
     If the device  100  determines that the detected IR light originating from one selected LEDs has become weaker than the remaining LEDs (YES of step  510 ), the device  100  reselects at least two other LEDs at step  512 . After reselection, at step  514 , the device  100  carries out a function based on detected IR light from the reselected LEDs. The reselected LEDs may include LEDs from the originally selected LEDs having the stronger detected IR light. The device  100  may repeat steps  510  to  514  in order to continually select the LEDs having the stronger reflected light to carry out the function. 
     Referring to  FIG. 6 , a procedure  600  is carried out by the electronic device  100 . At step  602 , the electronic device  100  projects IR light from the LEDs. At step  604 , the sensor  130  of the device  100  detects IR light originating from at least one of the LEDs reflected from off of a person. At step  606 , the device  100  selects, based on the detected IR light, two LEDs having the stronger reflected IR light. At step  608 , the device  100  may ignore the LEDs having no reflected light. 
     At step  610 , the device  100  may determine, based on the detected IR light, a difference between the detected IR light from the two selected LEDs having the stronger reflected IR light and the remaining LEDs having the weaker reflected IR light. Based on the determined difference, at step  612 , the device may increase the IR light projection of the remaining LEDs having the weaker reflected IR light. 
     Referring to  FIG. 7 , a procedure  700  is carried out by the electronic device  100 . Procedure  700  is directed to a facial and/or object illumination function using the IR LED system. Image recognition function is highly impacted by facial and/or object illumination. Without adequate illumination, image recognition failures are prevalent. Following the steps set forth in procedure  700 , the electronic device  100  may create a uniform broad illumination of a person&#39;s face. Furthermore, when combined with procedure  500  (i.e., repeated selection of LEDs having the stronger reflected IR light), the device  100  may be further optimized to drive LEDs to compensate for poor user-to-device orientations. 
     In more detail, at step  702 , the electronic device  100  projects IR light the LEDs. At step  704 , the sensor  130  of the device  100  detects IR light reflected from off of a person. At step  706 , the device  100  selects, based on the relative strength of the detected IR light, at least two of the LEDs (e.g., LEDs having the stronger reflected IR light). In another embodiment, the device  100  may select one LED, e.g., the LED with the strongest reflected IR light, and use the selected LED to illuminate the person&#39;s face. 
     Next, at step  708 , the device  100  projects IR light from the selected LEDs onto the person&#39;s face. The sensor  130  of the device receives IR light reflected off of the person&#39;s face at step  710 . Based on a characteristic of the received IR light, the device  100  determines the uniformity of the facial illumination at step  712 . Then at step  714 , based on the determined uniformity, the device  100  increases or decreases the projection of one or both of the two selected LEDs. 
     In an embodiment, the characteristic of the received IR light may include the relative strength of the received IR light from the LEDs. Based on the relative strength of the received IR light, the device  100  may further determine a difference between the received IR light from at least one LED having the stronger reflected IR light and at least one LED having the weaker reflected IR light. Based on the determined difference, the device  100  may increase the IR light projection of the LED or LEDs having the weaker reflected IR light. This embodiment is directed to an IR transceiver (LED and sensor) closed loop system, which may be used to enhance the facial illumination function as shown in procedure  700 . The IR transceiver closed loop system adaptively adjusts the LEDs&#39; IR light projections and coverage based on the received IR light signal to provide a more uniform illumination of the person&#39;s face. 
     Referring to  FIG. 8 , a procedure  800  is carried out by the electronic device  100 . Procedure  800  is directed to detecting gestures using IR LED groups. More specifically, in procedure  800 , each group of LEDs functions as a single LED. 
     At step  802 , the electronic device  100  projects IR light from a first group of LEDs. At step  804 , the device  100  projects IR light from a second group of LEDs. The sensor  130  of the device  100  then detects IR light reflected off of a person at step  806 . The device  100  then generates signals based on the detected IR light at step  808 . 
     At step  810 , if the device  100  determines that the detected IR light originates from any of the LEDs of the first group, the device  100  processes the signals as a single, first LED. At step  812 , if the device  100  determines that the detected IR light originates from any of the LEDs of the second group, the device  100  processes the signals as a single, second LED. At step  814 , based on whether the signals are processed as the first LED or the second LED, the device  100  determines whether the person is making a first gesture or a second gesture. 
     Referring to  FIG. 9 , a procedure  900  is carried out by the electronic device  100 . Procedure  900  is also directed to detecting gestures using IR LED groups. Unlike procedure  800 , however, the LED groups in procedure  900  functions as independent gesture detection systems. 
     At step  902 , the electronic device  100  detects its orientation. At step  904 , if the orientation of the device  100  is detected to be a portrait mode, the device  100  activates a first set of two LEDs. At step  906 , if the orientation of the device is detected to be a landscape mode, the device  100  then activates a second set of two LEDs. 
     After activation, at step  908 , the device projects light from either the first set of LEDs or the second set of LEDs. At step  910 , the sensor  130  of the device  100  detects reflected IR light originating from at least one of the two activated LEDs reflected off of a person. Based on the detected IR light, at step  912 , the device  100  carries out a function based on the detected reflected IR light from the activated set of LEDs. 
     In another embodiment, after activation and based on the detected orientation, the device may treat each set of LEDs as a single LED. For example, if the orientation of the electronic device  100  is detected to be a portrait mode, both LEDs in the first set of two LEDs may simultaneously project IR light. If the orientation of the electronic device  100  is detected to be a landscape mode, both LEDs in the second set of two LEDs may simultaneously project IR light. 
     Referring to  FIG. 10 , a procedure  1000  is carried out by the electronic device  100 . Procedure  1000  is directed to an IR proximity function. The IR proximity systems of conventional devices have a short range (about an inch) to eliminate the possibility of unintended false detection when an object or person comes near the devices. The short range may be problematic as a user sometimes moves the device toward his or her face in an odd orientation resulting in unintended actuation of the touch screen (proximity detection failure) before his or her face is detected. 
     In an embodiment, to perform the IR proximity function, two LEDs from the IR LED gesture detection system are used. The two LEDs should include the LED that is disposed closest to the sensor. For example, in the device  100  shown in  FIG. 1 , the first LED  120 , which is disposed closest to the sensor  130 , should be utilized for performing the IR proximity function. The other LED may be the second LED  122  or the fourth LED  126 , which are disposed closer to the first LED  120  than the third LED  124 . 
     The spacing between the first LED  120  and the sensor  130  may vary based on the distance between the cover glass of the housing  110  and the first LED  120 , the distance between the cover glass of the housing  110  and the sensor  130 , the projection area of the first LED  120 , and the reception area of the sensor  130 . To detect the presence of an object or a person at a close range (e.g., down to touching the cover glass such as the case when the person is conducting a phone call), the projection area of the first LED  120  and the reception area of the sensor  130  should intersect at or below the cover glass of the housing  110 . Accordingly, if the first LED  120  has a large projection area or if the sensor  130  has a large reception area, the first LED  120  or the sensor  130  may be disposed closer to the cover glass of the housing  110 . 
     In one embodiment, the sensor  130  of the IR LED gesture detection system is located in an area where the sensor  130  may detect a person&#39;s face touching the device  100  (e.g., near the speaker opening  112  of the top surface of the housing  110 ). If the sensor  130  is disposed at the bottom or sides of the device  100 , the IR LED gesture detection system will still detect IR proximity, but the IR proximity detection function may be falsely triggered by the user&#39;s hand carrying device  100  or dialing the device  100 , etc. 
     In addition, using two IR LEDs provides a voting ability of face presence detection that a single LED cannot. For instance, during a phone call, the first LED  120  and the second LED  122  may be used for performing the IR proximity function. The first LED  120  and the second LED  122  are cycled in time (e.g., TDMA). If reflected IR light from either of the first LED  120  and the second LED  122  is detected by the sensor  130 , the device  100  determines that a face is present and may deactivate the touch screen. However, because the second LED  122  is farther away from the sensor  130  than the first LED  120 , the second LED  124  is used to detect a person&#39;s approach before the person touches the cover glass of the housing  110  and supplements the first LED  120 , which can detect both approach and touch (intercept point design). In other embodiments, the first and second LEDs may be disposed right next to sensor (e.g., on either side of the sensor), and both LEDs may detect both approach and touch. 
     Referring to  FIG. 10 , at step  1002 , the electronic device  100  projects IR light from a first LED (i.e., the first LED  120 ). At step  1004 , the device  100  projects IR light from a second LED (e.g., the second LED  122  or the fourth LED  126 ). At step  1006 , the sensor  130  of the device  100  detects reflected IR light from off of a person. In the present embodiment, the sensor  130  is disposed closer to the first LED than the second LED (e.g., the sensor  130  is disposed closest to the first LED  120 ). 
     The device  100  may use the two LEDs in procedure  1000  to carry out a voting function based on whether the detected IR light originates from the first LED or the second LED. Based on the result of the voting function, the device  100  may determine whether to deactivate the touch screen. To carry out the voting function, one of the two LEDs may have a longer projection range than the other of the two selected LEDs, or one of the two LEDs may be disposed closer to the sensor  130  than the other. In such an embodiment, the device  100  will only deactivate the touch screen if the detected IR light originates from the first LED, and will carry out another function if the detected IR light originates from the second LED. For instance, at step  1008 , if the detected IR light originates from the first LED, the device  100  deactivates a touch screen of the device  100 . At step  1010 , if the device  100  determines that the detected IR light originates from the second LED (which is disposed farther from the sensor  130  than the first LED), the device  100  may detects the presence of the person and may perform a notification function indicating that a person is present or approaching the device  100 . 
     Referring to  FIG. 11 , a procedure  1100  is carried out by the electronic device  100 . Procedure  1100  is directed to an eye movement tracking function. During eye movement tracking, two LEDs from the IR LED gesture system are selected to project IR light onto a person&#39;s eye pupil. Projected IR light spots will appear on the eye. The device  100  then captures the IR light spots on the eye using a front facing camera of the device. For effective eye movement tracking, multiple LEDs are needed for depth detection. Furthermore, these LEDs should be disposed apart in order to appear as separate sources of IR light (e.g., about 2.5 inches of separation between the LEDs may be preferred). 
     Referring to  FIG. 11 , at step  1102 , the electronic device  100  projects IR light from a first LED onto a person&#39;s eye. At step  1104 , the device  100  projects IR light from a second LED. Then at step  1106 , the camera of the device  100  captures IR light spots on the person&#39;s eye from the first LED and the second LED. The device  100  tracks the IR light spots to detect movement of the eye in step  1108 . 
     The device  100  may further determine a characteristic of the captured IR light spots. The characteristic of the captured IR light spots may include the strength of the captured IR light spots. The characteristic may also include the angle at which the captured IR light spots is received. The characteristic may further include the direction from which the captured IR light spots is received. Using the determined characteristic, the IR LED detection system may dynamically adapt to any changes in the orientation or direction of the person&#39;s head or eyes. 
     In an embodiment, before performing procedure  1100 , the device  100  may determine which group of two LEDs of the plurality of LEDs is the most appropriate for tracking movement of the eye. In the IR LED gesture detection system described above, the device  100  may select and adaptively switch to the most suitable LEDs for tracking movement of the eye based on a user&#39;s looking direction. The user&#39;s looking direction relative to device  100  may be using the procedure  400  directed to IR LED selection. Thus, this IR LED selection for eye movement tracking is similar to the selection and reselection of LEDs described with respect to  FIGS. 4 and 5 . In this case, a camera of the device  100  may be used instead of the sensor  130 . 
     Furthermore, as discussed in with respect to  FIG. 5 , the reflected IR light from the selected LEDs is continuously monitored. This procedure may also be adapted to the eye movement tracking function. When the reflected IR light from a selected LED is weak, the device  100  may energize the weak LED for better eye movement tracking based on the face or object location relative to the device  100 . In other words, the device  100  may identify an LED of the plurality of LEDs that is weaker than the remaining LEDs, and the device  100  may then energize the identified LED. Accordingly, the IR LED gesture detection system helps to improve eye movement tracking via a continuous feedback loop. The IR LED gesture detection system may also be used to overcome background interference. 
     Referring to  FIG. 12 , a procedure  1200  is carried out by the electronic device  100 . Procedure  1200  is directed to cycling the plurality of LEDs to detect the approach or presence of a person and detect a gesture. First the device  100  detects whether the person is present or approaching the device  100 . At step  1202 , the LEDs project IR light. The sensor  130  detects IR light originating from at least one of the LEDs reflected from off of the person at step  1204 . Based on the detected IR light, the device  100  detects the presence of the person at step  1206 . Then at step  1208 , if the presence of the person is detected (e.g., the person is approaching the device  100 ), the device  100  carries out a function. The device  100  may turn on a screen, wake up the device  100 , display the time, initiate a notification, change a user interface, perform power optimization to turn the device  100  on or off, or reduce the power consumption of the device  100 . 
     Once the device  100  has detected the approach or presence of the person, the device  100  detects a gesture of the person, who may be dismissing a notification or may be instructing the device  100  to person another function. At step  1210 , the sensor  130  detects IR light originating from LEDs reflected from off of the person. Then at step  1212 , the device  100  detects the gesture of the person using the light of the LEDs. 
     For both person/object detection and gesture detection, the plurality of LEDs may project IR light sequentially. In other embodiments, to increase the detection range or coverage, the plurality of LEDs may project IR light simultaneously (e.g., when the device  100  performs the enhanced hand approach detection discussed above). 
     In addition to the exemplary functions described above, the IR LED gesture detection system may be adapted for carrying out other functions. For instance, the presence of four LEDs is highly beneficial to reliable IR transmission. When all LEDs projects IR light simultaneously, a super transmitter is achieved with longer range and broader coverage. Thus, when some LEDs are obstructed by user&#39;s hand, barcode data can still be transmitted using the unobstructed LED. 
     It can be seen from the foregoing that an electronic device with an IR LED gesture detection system and methods for using the gesture detection system have been provided. In view of the many possible embodiments to which the principles of the present discussion may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of the claims. Therefore, the techniques as described herein contemplate all such embodiments as may come within the scope of the following claims and equivalents thereof.