Abstract:
An optical sensor for detecting at least one of proximity and gesture is disclosed. The optical sensor is configured to detect or sense an object that is located out of the sensor&#39;s primary axis. This off-axis detection is facilitated by projecting light emitted by a light source away from the sensor&#39;s primary axis and away from the direction in which the light was originally emitted by the light source. The light detector is also configured to detect the light that is being projected off-axis.

Description:
FIELD OF THE DISCLOSURE 
       [0001]    The present disclosure is generally directed toward sensors and more specifically toward optical sensors for detecting proximity or gesture. 
       BACKGROUND 
       [0002]    Mobile communication devices, such as, for example, cellular telephones, smartphones, digital audio or video players, portable navigation units, laptop computers, personal digital assistants, tablets, netbooks, or the like are becoming increasingly popular. These devices may include, for example, a variety of sensors to support a number of applications in today&#39;s market. A popular market trend in sensor-based mobile technology may include, for example, applications that sense or recognize one or more aspects of a motion of a user relative to a mobile communication device and use such aspects as a form of a user input. For example, certain applications may sense or recognize waving gestures, finger gestures, air signatures, and the like of a user and may use such gestures as inputs representing various user commands in selecting music, playing games, estimating a location, determining navigation route, browsing through digital maps or Web content, authorizing transactions, or the like. 
         [0003]    Proximity sensors are similar to some gesture sensors on mobile communication devices in that proximity sensors may also utilize light and imagers to detect a user&#39;s proximity to the sensor. Proximity can also be used as inputs to applications on the mobile communication device, although proximity inputs typically provide less information than gesture inputs. In other words, proximity inputs are usually binary (the user is either within a detectable proximity of the sensor or not) whereas gesture inputs may correspond to detecting certain motions or actions of a user with the gesture sensor. 
         [0004]    A drawback to currently-available light-based sensors (proximity or gesture) is that the sensors are only capable of detecting proximity or gesture within a small detection window. More problematic is that the small detection window is required to be directly over the sensor itself. This means that user inputs at the sensor can only be detected when the user places a part of their body (or some other object) directly over the sensor. Requiring the user to provide such inputs in a small detection window has, to this point, limited the usefulness of light-based sensors in mobile communication devices. In particular, most users are interacting with a keypad or touch screen of the mobile communication device and do not want to have to change their interaction zone to some other location that is not coincident with the keypad or touch screen. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The present disclosure is described in conjunction with the appended figures: 
           [0006]      FIG. 1  depicts an isometric view of a sensor in accordance with embodiments of the present disclosure; 
           [0007]      FIG. 2A  depicts a first isometric view of a sensor sub-assembly in accordance with embodiments of the present disclosure; 
           [0008]      FIG. 2B  depicts a second isometric view of a sensor sub-assembly in accordance with embodiments of the present disclosure; 
           [0009]      FIG. 3  is a cross-sectional elevational view in the x-z plane of a light detector incorporated in a sensor in accordance with embodiments of the present disclosure; 
           [0010]      FIG. 4  is a cross-sectional elevational view in the x-z plane of a light source incorporated in a sensor in accordance with embodiments of the present disclosure; 
           [0011]      FIG. 5  depicts an isometric view of a sensor in accordance with embodiments of the present disclosure; 
           [0012]      FIG. 6  depicts an isometric view of a sensor in accordance with embodiments of the present disclosure; 
           [0013]      FIG. 7  depicts an isometric view of a sensor in accordance with embodiments of the present disclosure; 
           [0014]      FIG. 8  depicts an isometric view of a sensor in accordance with embodiments of the present disclosure; 
           [0015]      FIG. 9A  depicts an elevational view of an electronic device incorporating a sensor in accordance with embodiments of the present disclosure; 
           [0016]      FIG. 9B  depicts a top view an electronic device incorporating a sensor in accordance with embodiments of the present disclosure; 
           [0017]      FIG. 9C  depicts a field of view range of a sensor in accordance with embodiments of the present disclosure; 
           [0018]      FIG. 9D  depicts a viewing distance of a sensor in accordance with embodiments of the present disclosure; and 
           [0019]      FIG. 10  depicts an image plane relative to a sensor in accordance with embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The ensuing description provides embodiments only, and is not intended to limit the scope, applicability, or configuration of the claims. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the described embodiments. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the appended claims. 
         [0021]    Various aspects of the present disclosure will be described herein with reference to drawings that are schematic illustrations of idealized configurations. As such, variations from the shapes of the illustrations as a result, for example, manufacturing techniques and/or tolerances, are to be expected. Thus, the various aspects of the present disclosure presented throughout this document should not be construed as limited to the particular shapes of elements (e.g., regions, layers, sections, substrates, etc.) illustrated and described herein but are to include deviations in shapes that result, for example, from manufacturing. By way of example, an element illustrated or described as a rectangle may have rounded or curved features and/or a gradient concentration at its edges rather than a discrete change from one element to another. Thus, the elements illustrated in the drawings are schematic in nature and their shapes are not intended to illustrate the precise shape of an element and are not intended to limit the scope of the present disclosure. 
         [0022]    It will be understood that when an element such as a region, layer, section, substrate, or the like, is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. It will be further understood that when an element is referred to as being “formed” or “established” on another element, it can be grown, deposited, etched, attached, connected, coupled, or otherwise prepared or fabricated on the other element or an intervening element. 
         [0023]    Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top” may be used herein to describe one element&#39;s relationship to another element as illustrated in the drawings. It will be understood that relative terms are intended to encompass different orientations of an apparatus in addition to the orientation depicted in the drawings. By way of example, if an apparatus in the drawings is turned over, elements described as being on the “lower” side of other elements would then be oriented on the “upper” side of the other elements. The term “lower” can, therefore, encompass both an orientation of “lower” and “upper” depending of the particular orientation of the apparatus. Similarly, if an apparatus in the drawing is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The terms “below” or “beneath” can therefore encompass both an orientation of above and below. 
         [0024]    Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and this disclosure. 
         [0025]    As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0026]    Furthermore, various descriptive terms used herein, such as “transparent” should be given the broadest meaning possible within the context of the present disclosure. For example, something that is described as being “transparent” should be understood as having a property allowing no significant obstruction or absorption of electromagnetic radiation in the particular wavelength (or wavelengths) of interest, unless a particular transmittance is provided. 
         [0027]    With reference initially to  FIG. 1 , an example of a first sensor  100  will be described in accordance with embodiments of the present disclosure. The sensor  100  may be configured to operate as either a gesture sensor or a proximity sensor without departing from the scope of the present disclosure. The sensor  100  is shown to include a housing  104  having a top surface  108 , a plurality of side faces  112 , a front face  116 , and a back face  118 . In some embodiments the housing  104  is partitioned into two sections—a transmitter side and a receiver side. Accordingly, the housing  104  is depicted as further including a receiver hole  120  in the top surface  108  and a transmitter hole  124  in the top surface  108 . 
         [0028]    In the example of the first sensor  100 , the top surface  108  is shown to be substantially parallel with the depicted x-y plane, the side faces  112  are shown to be substantially parallel with the x-z plane, and the front face  116  and back face  118  are shown to be substantially parallel with one another and with the y-z plane. Thus, the top surface  108  is substantially orthogonal with the side faces  112 , which are both substantially orthogonal with the front face  116  and back face  118 . 
         [0029]    In accordance with at least some embodiments, the housing  104  may be constructed of any type of material that is suitable for attenuating or otherwise blocking light transmitted by a light source of the sensor  100 . Specifically, the housing  104  may provide two functions for the sensor  100 : (1) protection of the sensor  100  components and (2) preventing light from traveling directly from a light source of the sensor  100  to a light detector of the sensor  100 . Instead, the holes  120 ,  124  may be configured as the light path for the sensor  100  and any light detected at the light detector may first travel through the transmitter hole  124 , then impact or reflect off an object, then travel through the receiver hole  120 . Any other light emitted by the light source of the sensor  100  is substantially inhibited from traveling to the light detector. 
         [0030]    With reference now to  FIGS. 2A and 2B , additional components of the first sensor  100  will be described in accordance with embodiments of the present disclosure. In particular,  FIG. 2A  shows a sensor sub-assembly  200  or the sensor components that are housed within housing  104 . The sensor sub-assembly  200  is shown to include a substrate  204  with a receiver side  208  and transmitter side  212  mounted thereon. 
         [0031]    The receiver side  208  is shown to include a receiver mold component  216  and a receiver mold component  216 . As seen in  FIG. 2B , the receiver side  208  may also comprise a receiver Integrated Circuit (IC)  248 , a light detector  252 , and bonding wires  256  within the receiver mold component  216 . In some embodiments, the receiver mold component  216  corresponds to a plastic or similar type of material that is molded around the receiver IC  248 , light detector  252 , and bonding wires  256 , thereby encapsulating and protecting the components contained therein. In some embodiments, the receiver lens  220  may be integral to the receiver mold component  216 , meaning that the receiver lens  220  may be molded and formed of the same material as the rest of the receiver mold component  216 , but with a particular lens shape (e.g., a dome shape) that substantially focuses light toward the light detector  252 . In such an embodiment, the material of the receiver mold component  216  may be substantially transparent to wavelengths of light emitted by the transmitter side  212 . As an example, the receiver mold component  216  and/or receiver lens  220  may be substantially capable of allowing Infrared (IR) light or near-IR light to pass therethrough. In other embodiments, the receiver lens  220  is constructed of a different material from the rest of the receiver mold component  216 . In such a construction, the lens  220  may be substantially transparent to light emitted by the transmitter side  212  whereas the receiver mold component  216  may allow or block the light emitted by the transmitter side  212 . It may be generally desirable to utilize the construction where the receiver lens  220  is integral to the receiver mold component  216  to minimize assembly costs. 
         [0032]    As seen in  FIG. 2A , an intermediate layer  240  may be provided between the receiver mold component  216  and the substrate  204 . The intermediate layer  240  may include structural components that support the receiver mold component  216  on the substrate  204 . The structural components of the intermediate layer  240  may include an insulative material that substantially supports the weight of the receiver IC  248  on the substrate  204  as well as provides an electrical separation between the receiver IC  248  and substrate  204 . Electrical connections between contacts of the substrate  204  and the receiver IC  248  may be facilitated by the bonding wires  256  that extend from a top surface of the receiver IC  248  to a top surface of the substrate  204 . In some embodiments, the area provided on the top surface of the substrate  204  that is used for establishing electrical connections with the receiver IC  248  may be absent the insulative material of the intermediate layer  240 . 
         [0033]    In some embodiments, the substrate  204  may correspond to a Printed Circuit Board (PCB) or the like that supports the components of the receiver side  208  and transmitter side  212 . The substrate  204  may either be rigid or flexible. Moreover, the substrate  204  may comprise one or more conductive vias (not shown) that extend from a top surface of the substrate  204  to an opposing bottom surface of the substrate  204 . The bottom surface of the substrate  204  may further include one or more bonding pads  236  that enable the sensor  100  to be electrically connected to a larger PCB or some other electrical device. Thus, the electrical signals carried by the bonding wires  256  may be carried through the substrate  204  to the bonding pads  236  where they can be communicated to a larger circuit or set of circuits. In some embodiments, the bonding pads  236  may correspond to surface mount leads that enable the sensor  100  to be surface mounted to another PCB. Alternatively or additionally, the bonding pads  236  may comprise an array of bonding elements (e.g., a Ball Grid Array (BGA) or the like) that facilitate electrical connectivity between the sensor  100  and another PCB. 
         [0034]    The transmitter side  212  of the sensor sub-assembly  200 , much like the receiver side  208 , may comprise a transmitter mold component  224  and one or more optical elements configured to direct light emitted by a light source of the transmitter side  212 . In the depicted embodiment, the optical elements of the transmitter side  212  include a lens having a wedge portion  228  and a pill portion  232  that is seamlessly integrated with the wedge portion  228 . As will be discussed in further detail herein, the unique configuration of the wedge portion  228  and pill portion  232  enable the light transmitted by a light source  260  of the transmitter side  212  to be transmitted at an off-axis angle with respect to the major surface of the substrate  204  and with respect to a light-emitting surface of the light source  260 . 
         [0035]    Like receiver mold component  216 , the transmitter mold component  224  may be constructed of an optically-transparent and moldable material such as plastic, epoxy, glass, etc. In some embodiments, the wedge portion  228  and/or pill portion  232  may both be constructed from the same material as the transmitter mold component  224  and may even be integral with the rest of the transmitter mold component  224 . In other words, a single continuous material may be molded to create the wedge portion  228 , the pill portion  232 , and the rest of the transmitter mold component  224  that extends to the boundaries of the substrate  204 . It should be appreciated, however, that one or both of the wedge portion  228  and pill portion  232  may be constructed separate from the rest of the transmitter mold component  224  and may be attached thereto during a later manufacturing step. The transmitter mold component  224  may substantially encapsulate and protect the light source  260  and wire bonds established between the light source  260  and the substrate  204 . 
         [0036]    Also like the receiver mold component  216 , the transmitter mold component  224  may be attached to the substrate  204  by an intermediate layer  244 , which may actually correspond to the same material as the intermediate layer  240 . Furthermore, one or more bonding wires  264  may be used to electrically connect the light source  260  to the substrate  204 . One or more electrical signals used to control operation of the light source  260  may be provided to the light source  260  via an external circuit (e.g., a sensor driver) that is connected to the light source  260  via the bonding pads  236 . In other words, the signals transmitted to the light source  260  may be carried from the bonding pads  236  through conductive vias in the substrate  204  to the bonding wire  264  and eventually to the light source  260 . 
         [0037]    In accordance with at least some embodiments of the present disclosure, the light source  260  may correspond to any component or collection of components capable of producing and emitting light. As non-limiting examples, the light source  260  may comprise a Light Emitting Diode (LED), an array of LEDs, a laser diode, a collection of laser diodes, or the like. As a further non-limiting example, the light source  260  may correspond to a semiconductor-type light-emitting device that may or may not be constructed using flip-chip technology. In some embodiments, the light source  260  comprises a primary light-emitting surface (e.g., a top surface opposite the top surface of the substrate  204 ) that is substantially parallel or planar with the x-y plane. 
         [0038]    In accordance with at least some embodiments of the present disclosure, the light detector  252  may correspond to a photodetector, photodiode, a reverse-biased LED, a photoresistor, an image sensor (e.g., a CMOS image sensor), a Charge-coupled device (CCD), or the like that is mounted on the top surface of the receiver IC  248 . As a more specific, but non-limiting example, the light detector  252  may correspond an integrated optical circuit established on the IC  248  and a photodetector mounted on the IC  248 . 
         [0039]    With reference now to  FIG. 3 , additional details of the components included in the receiver side  208  will be described in accordance with embodiments of the present disclosure. The cross-sectional view of  FIG. 3  along the x-z plane shows how the light detector  252  can be offset relative to the receiver lens  220  to help adjust the viewing angle of the receiver side  208 . Even more specifically, the lens center  304  is shown to be offset relative to a light detector center  308 . In some embodiments, no portion of the light detector  252  intersects or lies directly beneath the lens center  304 . By offsetting the lens center  304  from the light detector center  308 , the viewing window the receiver side  208  is directed away from directly above the light detector  252  as in prior art sensors. Instead, the viewing window is directed toward the front face  116  of the housing  104 , thereby enabling the light detector  252  to detect objects that do not lie directly above the lens center  304  or the light detector center  308 . In other words, the sensor  100  can be configured to view objects that are beyond the front face  116  of the housing  104 . 
         [0040]    Another feature shown in  FIG. 3  is that the receiver hole  120  is offset relative to a center of the substrate  204 . Said another way, the receiver hole  120  is established on the top surface  108  of the housing  104 , but is biased toward the front face  116 , which means that the receiver hole  120  is closer to the front face  116  than the back face  118 . Likewise, the lens center  304  is centered within the receiver hole  120 , which means that the receiver lens  220  is biased toward the front face  116  of the housing. Conversely, the light detector center  308  is biased toward the back face  118 , thereby creating an optical path that is angular relative to the top surface of the even though the light-detecting surface of the light detector  252  is substantially planar with the x-y plane, the optical path for the light detector  252  is not parallel with the z-axis. 
         [0041]    With reference now to  FIG. 4 , additional details of the components included in the transmitter side  212  will be described in accordance with embodiments of the present disclosure. The cross-sectional view of  FIG. 4  along the x-z plane shows how the light source  260  can be offset relative to the lens elements of the transmitter side  212  as well as the substrate  204 . More specifically, and much like the receiver side  208 , the transmitter side  212  is configured such that a center of the light source  424  drawn through the center of the light source  260  and parallel with the z-axis is not coincident with the lens components of the transmitter mold component  224 . The pill portion  232  is shown to include a pill portion center  420  that is offset relative to the light source center  424 , thereby enabling the light emitted by the planar surface of the light source  260  to be directed away from the z-axis even though the light is initially transmitted from a light-emitting surface that is planar with the x-y plane. 
         [0042]    In the depicted embodiment, lens components of the transmitter side  212  include wedge portion  228  and pill portion  232 . The wedge portion  228  is shown to include a wedge rear face  404  and a wedge front face  408 . The pill portion  232  is shown to include a cylindrical portion  412  and front end  416 . The pill portion center  420  substantially bisects the cylindrical portion  412  of the pill portion  232 . The wedge front face  408  interfaces with the cylindrical portion  412  such that a singular and integrated lens is created in the transmitter mold component. Along with the wedge rear face  404  and the front end  416  of the pill portion  232 , light emitted by the light source  260  is bent toward the front face  116  of the housing  104 . Thus, an object that is neither above the pill portion center  420  or the light source center  424  can be illuminated with light emitted by the light source  260 . In some embodiments, an object can be illuminated by the light source  260  and detected by the light detector  252  even when the object is not positioned above the transmitter hole  124  and possibly when the object is positioned beyond the front face  116  of the sensor  100 . 
         [0043]    In some embodiments, the light source  260  is not aligned with the center of the substrate  204 . Instead, the light source  260  is biased toward the back face  118  of the housing  104 . Similarly, the light source  260  is biased toward the wedge portion  228  instead of the front end  416  of the pill portion  232 . This particular configuration enables light emitted by the light source  260  to be directed at an angle that is offset relative to the z-axis toward the front face  116 . 
         [0044]    Also like the receiver hole  120 , the transmitter hole  124  is shown to be biased toward the front face  116  of the housing  104 . The offset of the transmitter hole  124  enables the bent light to be transmitted at the angle relative to the z-axis. 
         [0045]    In some embodiments, the light source center  424  may not be exactly aligned with the light detector center  308  along the y-z plane; however, such a configuration could be possible. In other words, the light source center  424  may be closer or further away from the back face  118  than the light detector center  308  without departing from the scope of the present disclosure. Regardless of the relative position of the light source center  424  and light detector center  308 , the configuration of the lens elements enables the viewing angle of the sensor  100  to be directed away from a plane extending between the light source center  424  and light detector center  308  that is substantially orthogonal to the top surface of the substrate  104  (which consequently may also be orthogonal to the light-emitting surface of the light source  260  of the light-detecting surface of the light detector  252 ). This means that objects do not have to be positioned over the sensor  100  (e.g., coincident with the lens center  304 , light detector center  308 , pill portion center  420 , or light source center  424 ) to be detected by the sensor  100 . Advantageously, however, the structure of the sensor  100  components can still be substantially planar with respect to the substrate  204  on which they are mounted. This enables the sensor  100  to achieve a highly compact form factor while also enabling an extended and directional viewing window, thereby making the sensor  100  highly desirable for use in a number of electronic devices. 
         [0046]    With reference now to  FIGS. 5-8 , alternative configurations to that already described in connection with sensor  100 . In particular,  FIG. 5  shows a sensor  500  configuration where a support  508  is used to tilt the entirety of the sensor package  504  away from the z-axis. This particular configuration can help achieve a directional sensor that views objects not directly above the base of the support  508 . The support  508  can be used in combination with the sensor  100  configuration described above or the support  508  can be used with a traditional on-axis sensor package where the light emitted by the light source is emitted directly orthogonal to the light-emitting surface of the light source and objects are required to be directly above the light-emitting surface of the light source to be detected. 
         [0047]      FIG. 6  depicts another sensor  600  configuration where a receiver wedge  604  and transmitter wedge  608  are used to tilt the lens components of the receiver and transmitter, respectively. The receiver wedge  604  may tilt or rotate the lens components contained therein away from the z-axis. Likewise, the transmitter wedge  608  may tilt or rotate the lens components contained therein away from the z-axis thereby enabling the detection of objects off-axis from the sensor  600 . 
         [0048]      FIG. 7  depicts another sensor  700  configuration where alternative configurations of a receiver lens  704  and transmitter lens  708  are used to direct light away from the z-axis, thereby enabling the sensor  700  to detect objects positioned away from directly over the light source and/or light detector. In some embodiments, the receiver lens comprises a cylindrical or pill portion that has a longitudinal axis parallel with the y-axis. The transmitter lens  708  may also comprise a cylindrical or pill portion that has a longitudinal axis parallel with the x-axis. These lenses may help to direct the viewing angle of the sensor  700  toward the front face  116  of the housing; however, because a wedge portion is not used, the viewing range and/or viewing window may not be as large as the viewing window achieved by sensor  100 . 
         [0049]      FIG. 8  depicts another sensor  800  configuration where a planar or dome-shaped receiver lens  804  is used in combination with a cylindrical transmitter lens  808 . As with sensor  700 , the configuration of sensor  800  may achieve a certain amount of off-axis object detection, but the range and viewing window of the sensor  800  may be limited as compared to the range and viewing window of sensor  100 . 
         [0050]    It should be appreciated that the sensors  500 ,  600 ,  700 , and  800  may not be as compact and/or have the same viewing range/window as sensor  100 . 
         [0051]    With reference now to  FIGS. 9A-D , additional capabilities of a sensor  904  incorporated into an electronic device  900  will be described in accordance with embodiments of the present disclosure. The sensor  904  may correspond to any of the sensors  100 ,  500 ,  600 ,  700 , and/or  800  described herein above. In some embodiments, the sensor  904  may correspond to the sensor  100  configuration having a highly compact form factor as well as the ability to detect or sense an object  908  that is not aligned above the sensor  904  with respect to the z-axis. 
         [0052]    In some embodiments, the object  908  may correspond to any physical and/or movable element. As a non-limiting example, the object  908  may correspond to a limb, hand, finger, thumb, or the like of a user of the electronic device  900 . Alternatively or additionally, the object  908  may correspond to a stylus or other object having a predetermined shape. In some embodiments, the sensor  904  is configured to detect a proximity of the object  908  relative to the sensor  904  and/or the electronic device  900 . In some embodiments, the sensor  904  is configured to detect gesture inputs provided by a user by tracking a motion or series of motions of the object  908  relative to the sensor  904 . Advantageously, proximity or gesture can be detected with the sensor  904  even though the object  908  is not positioned directly above the sensor  904 . 
         [0053]    In some embodiments, the object  908  does not have to cross the y-z plane that intersects the sensor  904 , which may also be referred to herein as the primary sensor plane. In other embodiments, the primary sensor plane may not be exactly coincident with the y-z plane, but, instead, may coincide with a plane established substantially perpendicular to the major surface of the substrate  204  and along a line extending between the light source and light detector of the sensor  904 . Another definition of the primary sensor plane may correspond to a plane that is perpendicular to the light-emitting surface of the light source (or the light-detecting surface of the light detector) and along a line extending between the light source and light detector of the sensor  904 . Under any definition, the primary sensor plane may basically travel through the sensor  904  and be approximately parallel with the y-z plane. 
         [0054]    In some embodiments, the object  908  can be illuminated and detected by the sensor  904  when the object is displaced from the primary sensor plane intersecting the sensor  904  by a distance of DX. As an example, DX may correspond to a distance of at least six (6) inches; thus, the object  908  can be detected when it is six (6) inches away from the primary sensor plane. The object  908  can also be detected when it is displaced from a display screen  912  of the electronic device  900  by a height of H. In some embodiments, the object  908  may be detected even if the object is positioned more than 15 degrees away from the primary sensor plane. As shown in  FIG. 9D , the field of view of the sensor  904  does not even have to coincide with the primary sensor plane and the field of view may be at least 60 degrees wide. In other embodiments, the field of view of the sensor  904  may extend at least 80 degrees offset from the primary sensor plane (e.g., within 10 degrees of the display surface  912 ) and the field of view can extend at least 6 inches away from the primary sensor plane. This particular field of view substantially enables the detection of the object  908  over the display screen  912  instead of over the sensor  904 , thereby increasing the potential gestures that can be captured with the sensor  904  for controlling operations of the electronic device  900 . 
         [0055]    In some embodiments, the sensor  904  can be configured to detect the object  908  by illuminating the object  908  with light from the light source and then detecting light that reflects off the object with the light detector. In some embodiments, the reflected light from the object  908  can be detected by the light detector even though the reflected light has an obtuse angle of incidence relative to the primary sensor plane (e.g., the y-z plane passing through the light source and light detector). Moreover, the field of view may include the primary sensor plane as shown in  FIG. 9C , but the field of view is not required to coincide with the primary sensor plane as shown in  FIG. 9D  and the maximum detection distance DMAX for an object may be as far away as 20 cm or more even when the object  908  is offset from the primary sensor plane by 45 degrees. In some embodiments, the object  908  may be detected even when the reflected light detected at the light detector arrives at the light detector at an acute angle of incidence measured relative to the light-detecting surface of the light detector. The reflected light detected at the light detector may then be correlated to at least one of a proximity and gesture input. 
         [0056]      FIG. 10  further illustrates the optical operation of a sensor according to embodiments of the present disclosure. In particular, a sensor is configured to create an illumination area  1004  that is off-axis relative to the light-emitting surface of the light source and also off-axis relative to the primary sensor plane passing through the light source and light detector. Likewise, the light detector is configured such that the receiver&#39;s view window  1008  is also off-axis, but substantially aligned with the transmitter illumination area  1004  in an image plane  1000 . The image plane  1000  is neither orthogonal with the primary sensor plane nor is the image plane  1000  orthogonal with the light-emitting and/or light-detecting surfaces of the sensor&#39;s light source and/or light detector, respectively. Creating such an image plane  1000  enables the sensor to be utilized in a much more flexible manner than traditional light-based sensors. 
         [0057]    Specific details were given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. 
         [0058]    While illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.