PATENT DOCUMENT

Publication Number: US-9291495-B2
Application Number: US-201313787434-A
Country: US
Kind Code: B2

Title: Proximity sensor with combined light sensor having an increased viewing angle

Abstract:
A proximity and light sensing device including a radiation emitter for proximity sensing positioned on a substrate. The device further includes a radiation detector positioned on the substrate, the radiation detector configured to detect radiation from the emitter. An ambient light detector is also positioned on the substrate and around the radiation emitter so as to form a border around the radiation emitter and detect off-axis ambient light rays.

Claims:
What is claimed is:  
     
       1. A proximity and light sensing apparatus comprising:
 a radiation emitter for proximity sensing positioned on a substrate; 
 a radiation detector positioned on the substrate, the radiation detector configured to detect radiation from the emitter; and 
 an ambient light detector positioned on the substrate and around the radiation emitter so as to form a border substantially entirely around the radiation emitter and detect off-axis ambient light rays. 
 
     
     
       2. The proximity and light sensing apparatus of  claim 1  wherein the ambient light detector is configured to detect off-axis ambient light rays that are at least 20 degrees off-axis. 
     
     
       3. The proximity and light sensing apparatus of  claim 1  wherein the ambient light detector is configured to detect East off-axis ambient light rays. 
     
     
       4. The proximity and light sensing apparatus of  claim 1  wherein the ambient light detector is configured to detect West off-axis ambient light rays. 
     
     
       5. The proximity and light sensing apparatus of  claim 1  wherein the ambient light detector is a first ambient light detector, wherein the apparatus further comprises:
 a second ambient light detector positioned on the substrate and around the radiation detector. 
 
     
     
       6. The proximity and light sensing apparatus of  claim 5  wherein the second ambient light detector forms a border around only a portion of the radiation detector. 
     
     
       7. The proximity and light sensing apparatus of  claim 1  wherein the ambient light detector is configured to detect ambient light outside of a viewing angle of the radiation emitter. 
     
     
       8. The proximity and light sensing apparatus of  claim 1  wherein the radiation detector is configured to detect infrared (IR) radiation emitted from the radiation emitter and visible light from the ambient environment. 
     
     
       9. A proximity and light sensing apparatus comprising:
 a first compartment having a radiation emitter for proximity sensing positioned on a substrate and an optical element positioned along a side of the radiation emitter opposite the substrate; 
 a second compartment having a radiation detector positioned on the substrate and an optical element positioned along a side of the radiation detector opposite the substrate; 
 a mid wall extending in a direction substantially normal to the substrate, the mid wall positioned between the first compartment and the second compartment; and 
 an ambient light detector positioned within the first compartment and substantially surrounding the radiation emitter, wherein the ambient light detector is dimensioned to detect East off-axis ambient light rays directed toward a portion of the substrate between the radiation emitter and the mid wall. 
 
     
     
       10. The proximity and light sensing apparatus of  claim 9  wherein the first compartment comprises only one optical element and the ambient light detector detects East off-axis ambient light rays transmitted through the only one optical element. 
     
     
       11. The proximity and light sensing apparatus of  claim 9  wherein the ambient light detector is between the radiation emitter and the mid wall and the off-axis ambient light rays are at least 20 degrees off-axis. 
     
     
       12. The proximity and light sensing apparatus of  claim 9  wherein the ambient light detector is further dimensioned to detect off-axis West rays. 
     
     
       13. The proximity and light sensing apparatus of  claim 9  wherein the radiation detector is configured to detect infrared (IR) radiation emitted from the radiation emitter and visible light from the ambient environment. 
     
     
       14. The proximity and light sensing apparatus of  claim 9  wherein the radiation emitter is configured to emit IR radiation and detect visible light from the ambient environment. 
     
     
       15. A proximity and light sensing apparatus comprising:
 a first compartment having a radiation emitter and an ambient light detector, wherein the radiation emitter is positioned on a substrate and the ambient light detector is positioned substantially entirely around the radiation emitter and the ambient light detector is configured to detect ambient light outside of a viewing angle of the radiation emitter; and 
 a second compartment having a radiation detector positioned on the substrate, wherein the radiation detector is configured to detect radiation emitted from the radiation emitter. 
 
     
     
       16. The proximity and light sensing apparatus of  claim 15  wherein the ambient light detector is a first ambient light detector, wherein the apparatus further comprises:
 a second ambient light detector positioned on the substrate and around the radiation detector, wherein the second ambient light detector is configured to detect ambient light rays outside of a viewing angle of the radiation detector. 
 
     
     
       17. The proximity and light sensing apparatus of  claim 15  wherein the ambient light detector is configured to detect ambient light rays which are at least 20 degrees off-axis with respect to an optical axis of the radiation emitter. 
     
     
       18. The proximity and light sensing apparatus of  claim 15  wherein the ambient light detector is a first ambient light detector, wherein the apparatus further comprises:
 a second ambient light detector positioned on the substrate and around the radiation detector, wherein the second ambient light detector is configured to detect off-axis ambient light rays which are at least 20 degrees off-axis with respect to an optical axis of the radiation detector in an East direction. 
 
     
     
       19. The proximity and light sensing apparatus of  claim 15  wherein the radiation detector is configured to detect infrared (IR) radiation emitted from the radiation emitter and visible light from the ambient environment.

Description:
FIELD 
     An embodiment of the invention is directed to a light and proximity sensing device having an increased sensor viewing angle. Other embodiments are also described and claimed. 
     BACKGROUND 
     Portable handheld electronic devices, such as the iPhone® multifunction device by Apple Inc., have a touch screen in their front face, where an earpiece speaker or receiver used for telephony is located. When the device is being held against the user&#39;s ear during a phone call, a proximity function automatically senses this condition using an infrared proximity sensor that is built into the device, and on that basis turns off the touch sensitive display screen of the device. The proximity function can also automatically determine or measure when the device has moved away from the user&#39;s ear, in which case the touch screen is re-activated. This is achieved by measuring the signals of the infrared proximity sensor&#39;s emitter and complementary detector, where the emitter transmits an infrared signal that is reflected by a nearby object (e.g., the user&#39;s head) and picked up by the detector. A stronger received signal may be interpreted by the proximity function to mean that the object is closer, while a weaker received signal means the object is farther away. 
     In many instances, the proximity sensor is combined with an ambient light sensor (ALS) which senses ambient visible light intensity. An ambient light detector process uses the sensed visible light intensity to, for example, adjust the touch screen display lighting. The ALS should have a field of view (FOV) and viewing angle which is larger than that of the proximity sensor, so that light from all different directions can be detected. When the proximity sensing device and the ALS device are packaged very close together, however, the FOV and viewing angle of the ALS may be limited to that of the proximity sensing device. 
     SUMMARY 
     An embodiment of the invention is directed to a light and proximity sensing device having an increased ambient light viewing angle. To achieve the proximity function, the proximity and light sensing device may include a first compartment having a radiation emitter positioned on a substrate and an optical element positioned over the radiation emitter. A second compartment may further be provided which includes a radiation detector positioned on the substrate and an optical element aligned with an optical path to the detector. A mid wall is positioned between the first compartment and the second compartment to prevent cross talk between the emitter and detector. 
     The ALS function, with an increased viewing angle, may be provided by an ambient light detector positioned around one or both of the radiation emitter and the radiation detector such that it forms an ambient light detector border around the radiation emitter and/or the radiation detector. Since the ambient light detector extends outside of the radiation emitter and/or detector, it forms a wider viewing angle than the radiation emitter and/or detector. In some embodiments, the ambient light detector is configured to have a viewing angle capable of capturing rays which are more than 20 degrees off-axis with respect to an optical axis, for example, from about 20 degrees to 45 degrees off-axis. In some embodiments, the off-axis rays are East off-axis rays, meaning they are off-axis in the East direction. In other embodiments, ambient light detector is configured to detect off-axis rays in many different directions, for example, East off-axis rays, West off-axis rays, North off-axis rays and/or South off-axis rays. It is further contemplated that in some embodiments, the radiation emitter and/or the radiation detector may have the ALS function incorporated therein, such as by integrating an ambient light photodetector therein, to further enhance ALS performance of the device within which the sensing device is implemented. 
     The above summary does not include an exhaustive list of all aspects of the present invention. It is contemplated that the invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the Detailed Description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and they mean at least one. 
         FIG. 1A  is a cross-sectional side view of one embodiment of a sensing device. 
         FIG. 1B  is a top view of one aspect of the sensing device of  FIG. 1A . 
         FIG. 1C  is a cross-sectional side view of one aspect of the sensing device of  FIG. 1A . 
         FIG. 1D  is a cross-sectional side view of one aspect of the sensing device of  FIG. 1A . 
         FIG. 2A  is a cross-sectional side view of another embodiment of a sensing device. 
         FIG. 2B  is a top view of one aspect of the sensing device of  FIG. 2A . 
         FIG. 2C  is a cross-sectional side view of one aspect of the sensing device of  FIG. 2A . 
         FIG. 2D  is a cross-sectional side view of one aspect of the sensing device of  FIG. 2A . 
         FIG. 3  is a cross-sectional side view of another embodiment of a sensing device. 
         FIG. 4  is a perspective view of a handheld device within which embodiments of a sensing device may be implemented. 
         FIG. 5  is a block diagram of a system in which embodiments of a sensing device may be implemented. 
     
    
    
     DETAILED DESCRIPTION 
     In this section we shall explain several preferred embodiments of this invention with reference to the appended drawings. Whenever the shapes, relative positions and other aspects of the parts described in the embodiments are not clearly defined, the scope of the invention is not limited only to the parts shown, which are meant merely for the purpose of illustration. Also, while numerous details are set forth, it is understood that some embodiments of the invention may be practiced without these details. In other instances, well-known structures and techniques have not been shown in detail so as not to obscure the understanding of this description. 
       FIG. 1A  is a cross-sectional side view of one embodiment of a sensing device. In the illustrated embodiment, sensing device  100  includes a radiation emitter  102  and a radiation detector  104 . The radiation emitter  102  may generate and emit radiation in, for example, the infrared (IR) bands. Representatively, radiation emitter  102  may be a semiconductor radiation source such as a light emitting diode (LED). The radiation detector  104  may be configured to detect changes in the intensity of radiation emitted from radiation emitter  102 . In this aspect, radiation detector  104  may provide a proximity sensor function. Representatively, radiation detector  104  may be a photodiode or other type of photodetector capable of sensing and converting IR radiation into a current or voltage that can then be processed by the device within which it is implemented. 
     In some embodiments, sensing device  100  may further include an ambient light detector  130  to provide an ALS function to sensing device  100 . Ambient light detector  130  may detect an intensity of ambient light from the surrounding environment. For example, the ambient light detector  130  may sense an intensity of visible light within the environment, such as that from the sun or other indoor/outdoor lighting sources (e.g., light bulbs). Based on the intensity of light sensed, the device within which sensing device  100  is implemented may modify its operation (e.g., display screen functionality and/or lighting). The ambient light detector  130 , however, requires a relatively wide viewing angle (e.g., at least ±30 degrees of the optical axis) to ensure that screen brightness is maintained as the user tilts or moves the device within which sensing device  100  is implemented. In some cases, this viewing angle may be wider than that desired for proper proximity sensor function of sensing device  100 , which requires well-collimated optics. 
     To accommodate the competing optical requirements of the ALS function and the proximity function of sensing device  100 , ambient light detector  130  may be positioned within sensing device  100  such that it has a viewing angle capable of capturing ambient light rays outside of a viewing angle of the proximity sensing components (e.g., radiation emitter  102  and/or radiation detector  104 ). Representatively, in one embodiment, ambient light detector  130  may be configured to detect East rays  132  which are off-axis to optical axis  126  as illustrated by angle (β) in an East direction (as viewed in  FIG. 1A ). Ambient light detector  130  may further be configured to detect West rays which are off-axis to optical axis  126  as illustrated by angle (α) in a West direction (as viewed in  FIG. 1A ). It is to be understood that the terms “off-axis ray” or “off-axis rays” are intended to refer to one or more incoming light rays which form, for example, an angle (β) or an angle (α) with respect to optical axis  126 . In other words, they are not parallel to optical axis  126 . 
     In some embodiments, the off-axis angles β and α of East rays  132  and West rays  134 , respectively, may be at least 20 degrees off-axis, for example, at least 30 degrees off-axis, and in some cases, from about 15 degrees off-axis to about 45 degrees off-axis, for example, from 25 degrees to 35 degrees off-axis. Such off-axis rays of this degree are typically difficult to detect due to the collimated optics needed for proximity function, which often times prevents the detection of light rays more than 20 degrees off-axis. Due to the increased viewing angle of ambient light detector  130 , the ALS function can be added to the proximity sensing function of sensing device  100  without changing the overall design packaging to accommodate the ALS requirements. 
     In one embodiment, the wide viewing angle of ambient light detector  130  may be achieved by positioning ambient light detector  130  entirely around radiation emitter  102 . In this aspect, ambient light detector  130  forms a border or frame around radiation emitter  102  as illustrated in  FIG. 1B .  FIG. 1B  shows a top view of one arrangement of the ambient light detector  130 , radiation emitter  102  and radiation detector  104 . It is noted that since ambient light detector  130  is positioned around all sides of radiation emitter  102 , in addition to East and West off-axis rays, it may further be capable of detecting North and South off-axis rays. In some embodiments, depending upon the dimensions of radiation emitter  102 , ambient light detector  130  may form a substantially square shaped frame structure having an overall footprint length and width of from about 0.5 mm to about 0.8 mm, for example, from 0.6 mm to 0.7 mm, representatively, 0.65 mm. Alternatively, ambient light detector  130  may be positioned around only a portion of radiation emitter  102  where ambient light detection is desired. For example, ambient light detector  130  may be formed around only one side, two sides, or three sides of radiation emitter  102 . In any case, since ambient light detector  130  is positioned outside of radiation emitter  102 , it forms a wider viewing angle than that of radiation emitter  102  as will be described in more detail in reference to  FIG. 1C . 
     It is further to be understood that in addition to the positioning of ambient light detector  130 , its width around radiation emitter  102  may further have an effect on the ambient light rays that can be sensed. In other words, increasing a width of ambient light detector  130  may increase the viewing angle while decreasing the width may decrease the viewing angle In this aspect, in some embodiments, ambient light detector  130  may extend all the way from a side of radiation emitter  102 , which faces mid wall  110 , to mid wall  110  to allow for optimal off-axis East ray detection. It is further noted that ambient light detector  130  may be a photodiode or other type of photodetector capable of sensing and converting visible light into a current or voltage that can then be processed by the device within which it is implemented. Since ambient light detector  130  detects or senses visible light, IR radiation emitted from radiation emitter  102  will not interfere with the ALS function. 
     It is further to be understood that in some embodiments, radiation detector  104  may also be capable of detecting ambient light so as to enhance an ALS performance of sensing device  100 . For example, radiation detector  104  may have both radiation detecting sensors and ambient light detecting sensors incorporated therein. In this aspect, ambient light detector  130  can be used to detect the wide angle off-axis ambient light rays and the additional ambient light sensor incorporated within radiation detector  104  can detect rays within the viewing angle of the proximity sensing components (e.g., rays less than about 20 degrees off-axis) such that both ambient light rays within and outside of the collimated optics of sensing device  100  can be detected. 
     Returning briefly to the overall assembly of each of the ALS and proximity sensing components within sensing device  100 , in some embodiments, radiation emitter  102  and ambient light detector  130  may be mounted or formed within a portion of a substrate  112  within a first compartment  106  formed over substrate  112 . Radiation detector  104  may be mounted or formed within a portion of substrate  112  within a second compartment  108 . In one embodiment, substrate  112  is a printed circuit board (PCB) having traces, wire bond pads and vias disposed thereon or therein to facilitate transfer of electrical signals between radiation emitter  102 , radiation detector  104  and ambient light detector  130  and the electronic device within which sensing device  100  is implemented. Radiation emitter  102  may also be electrically coupled to proximity sensor circuitry  144  and radiation detector  104  may be electrically coupled to proximity sensor circuitry  140 . In addition, ambient light detector  130  may be electrically coupled to ALS circuitry  142 . The circuitry may be signal processing circuitry that allows signals associated with the radiation emitter  102 , ambient light detector  130  and/or radiation detector  104  to be used by the electronic device to modify its operation (e.g., turn a display screen off). 
     The first and second compartments  106 ,  108  may be formed on opposing sides of a mid wall  110 . Mid wall  110  extends from substrate  112  and prevents cross talk between emitter  102  and detector  104 . Cross talk refers to an occurrence in which stray light from an emitter is detected by the detector thereby causing an undesired false signal mimicking a true proximity or object detection signal. Mid wall  110  may therefore be made of any type of material capable of blocking emitter stray signals from the detector, for example, a ceramic, a metal, a polyimide or other similar material opaque to IR radiation. 
     Sensing device  100  may further include optical element  118  and optical element  120 . Optical elements  118 ,  120  may be lenses fitted within openings  114 ,  116  formed within a top wall of each of compartments  106 ,  108 . Optical element  118  is positioned over radiation emitter  102  such that light emitted from radiation emitter  102  passes through optical element  118  to the ambient environment. Optical element  118  may further be positioned over ambient light detector  130  such that ambient or visible light from the outside environment can pass through optical element  118  to ambient light detector  130 . Optical element  120  is positioned over radiation detector  104  such that radiation from emitter  102 , which is reflected off a nearby object, can pass through optical element  120  to radiation detector  104 . Each optical element  118 ,  120  may be configured to transmit and refract the incoming or outgoing light beams in the desired direction. For example, in some embodiments, optical elements  118 ,  120  may be drum lenses which can concentrate the transmitted light and therefore increase the amount of light focused at the nearby object or radiation detector  104 . This is particularly advantageous in the case of proximity detection because it can increase proximity detection distances. It is to be understood, however, that although exemplary optical elements are described herein, such features are optional and may be omitted in some embodiments. 
     In some embodiments, a window  122  may further be positioned over radiation emitter  102 , radiation detector  104  and ambient light detector  130 . Window  122  may be formed from a translucent or semi-translucent material such that it does not substantially modify the optical characteristics of sensing device  100 . Window  122  may be part of sensing device  100  or formed as part of the portable electronic device in which sensing device  100  is implemented. 
     Returning now to the viewing angle of ambient light detector  130 , such viewing angle may be better understood by comparing the viewing angle of ambient light detector  130  and the viewing angle of radiation emitter  102 . Such a comparison is illustrated in  FIG. 1C . In particular,  FIG. 1C  illustrates the wider viewing angle of ambient light detector  130 . As previously discussed, in the case of ALS, it is desirable for ambient light detector  130  to be able to sense or detect incoming light from all different directions. In other words, it is desirable for ambient light sensor  130  to have a wider viewing angle than radiation emitter  102 , for which more collimated optics are desired. The term “viewing angle” refers to an angle of the cone defining the sensor&#39;s field of view (FOV). It is to be understood that the term “field of view” or “FOV” is used generally herein to refer to the area that is visible from the view point of a particular sensor.  FIG. 1D  illustrates the ambient light detector FOV  160 A and  160 B, in comparison to the radiation emitter FOV  162 , which have been omitted from  FIG. 1C  for purposes of clarity. 
     For proximity detection, however, sensing device  100  does not require such a wide viewing angle. The performance of the ALS function may therefore be compromised when, for example, the ALS is integrated within the existing proximity sensor packaging, which is designed with a narrower viewing angle in mind. Moreover, even where the packaging is designed for an integrated ALS and proximity sensing system, the FOV and viewing angle may be limited by the size of the opening (e.g., opening  114  and opening  116 ) through which the incoming light beams travel and, in some cases, the associated optical element (e.g., optical element  118  or optical element  120 ). This is particularly true with small portable devices such as cellular telephones in which the sensing device  100  package may be confined to, for example, an approximately 2.4 mm by 2.7 mm square footprint. In addition, due to the relatively small package size, radiation emitter  102 , ambient light detector  130  and radiation detector  104  are confined to a size no larger than their respective compartment sizes. 
     As a result, off-axis rays (e.g., off-axis rays  132  and  134  illustrated in  FIG. 1A ), which are off-axis with respect to an optical axis  126  of optical element  118 , in some cases around 30 degrees, may be outside of the relatively narrow viewing angle  150  of radiation emitter  102 , which typically has a viewing angle less than 20 degrees. Since ambient light detector  130 , however, is positioned around radiation emitter  102  as illustrated, it has a wider viewing angle  152  than that of radiation emitter  102  as illustrated by angle (Δ). For example, in some cases, the radiation emitter viewing angle  150  may be less than 20 degrees and the ambient light detector viewing angle  152  may be from about 20 degrees to about 45 degrees. In such cases, angle (Δ) may be from about 0 degrees to about 25 degrees, for example, from about 10 to about 20 degrees or about 15 degrees. In other words, the ambient light detector viewing angle  152  is anywhere from 0 to about 25 degrees greater than that of radiation emitter viewing angle  150 , and therefore ambient light detector  130  can detect light rays having an off-axis angle anywhere from 0 to 25 degrees outside of a FOV (e.g., FOV  162  illustrated in  FIG. 1D ) of radiation emitter  102 . 
       FIG. 2A  is a cross-sectional side view of another embodiment of a sensing device. Sensing device  200  is substantially similar to sensing device  100  except that in this embodiment, sensing device  200  includes an additional ambient light detector  231  positioned near radiation detector  204  to enhance ALS function. Representatively, sensing device  200  includes a radiation emitter  202  and a radiation detector  204 . The radiation emitter  202  may generate and emit radiation in, for example, the infrared (IR) bands. For example, radiation emitter  202  may be a semiconductor radiation source such as a light emitting diode (LED). The radiation detector  204  may be configured to detect changes in the intensity of radiation emitted from emitter  202 . In this aspect, radiation detector  204  may provide a proximity sensing function. Representatively, radiation detector  204  may be a photodiode or other type of photodetector capable of sensing and converting IR radiation into a current or voltage that can then be processed by the device within which it is implemented. 
     Sensing device  200  may further include an ambient light detector  230  and an ambient light detector  231  to provide an ALS function to sensing device  200 . Ambient light detectors  230 ,  231  may detect an intensity of ambient light from the surrounding environment. For example, the ambient light detectors  230 ,  231  may sense an intensity of visible light within the environment, such as that from the sun or other indoor/outdoor lighting sources (e.g., light bulbs). Based on the intensity of light sensed, the device within which sensing device  200  is implemented, may modify its operation (e.g., display screen functionality and/or lighting). As previously discussed, however, for optimal ALS performance, it is desirable for ambient light detectors  230 ,  231  to have a relatively wide viewing angle (e.g., at least ±30 degrees of the optical axis) to ensure, for example, that screen brightness is maintained as the user tilts or moves the device within which sensing device  200  is implemented. The desired viewing angle may, however, be wider than that desired for proper proximity sensor function of sensing device  200 . 
     To accommodate the competing optical requirements of the ALS function and the proximity function of sensing device  200 , ambient light detector  230  may be similar to ambient light detector  130  previously discussed in reference to  FIG. 1A  in that it is positioned around radiation emitter  202 . In this aspect, ambient light detector  230  has a viewing angle sufficient to capture East rays  132  which are off-axis to optical axis  226  as illustrated by angle (β′) in an East direction (as viewed in  FIG. 2A ). Ambient light detector  230  may further be configured to detect West rays which are off-axis to optical axis  226  as illustrated by angle (α′) in a West direction (as viewed in  FIG. 2A ). In some embodiments, the off-axis angles β′ and α′ of East rays  232  and West rays  234 , respectively, may be at least 20 degrees off-axis, for example, at least 30 degrees off-axis, and in some cases, from about 15 degrees off-axis to about 45 degrees off-axis, for example, from 30 degrees to 35 degrees off-axis. 
     To further enhance off-axis ray detection, ambient light detector  231  may be positioned near radiation detector  204 . In some embodiment, ambient light detector  231  may be configured to have a viewing angle sufficient to capture East rays  233  which are off-axis to optical axis  256  as illustrated by angle (θ) in an East direction (as viewed in  FIG. 2A ). In some embodiments, the off-axis angle of East rays  233  may be at least 20 degrees off-axis, for example, at least 30 degrees off-axis, and in some cases, from about 15 degrees off-axis to about 45 degrees off-axis, for example, from 30 degrees to 35 degrees off-axis. Thus, ambient light detector  231  may have a viewing angle sufficient to capture off-axis rays within a range of from about 20 degrees to about 40 degrees off-axis. 
     In one embodiment, the wide viewing angle, particularly to East off-axis rays, of ambient light detector  231  may be achieved by positioning ambient light detector  231  within a path of East off-axis rays  233 . Representatively, ambient light detector  231  may be positioned along a left side of radiation detector  204  (e.g., a side between radiation detector  204  and the outer wall as viewed in  FIG. 2A ). Ambient light detector  231  may also extend around the top and bottom sides of radiation detector  204  as viewed in  FIG. 2B  such that it forms a substantially “c” shaped structure to allow for detection of North and South off-axis rays.  FIG. 2B  shows a top view of one arrangement of the ambient light detectors  230 ,  231 , radiation emitter  202  and radiation detector  204 . Alternatively, ambient light detector  231  may be positioned around the entire radiation detector  204  such that it forms a border around radiation detector  204  and can detect off-axis rays from many different directions (e.g., East, West, South and North off-axis rays). In any case, since ambient light detector  231  is positioned outside of radiation detector  204 , it forms a wider viewing angle than that of radiation detector  204  as will be described in more detail in reference to  FIG. 2C . It is further noted that ambient light detectors  230  and  231  may be photodiodes or another type of photodetector capable of sensing and converting visible light into a current or voltage that can then be processed by the device within which it is implemented. Since ambient light detectors  230  and  231  detect or sense visible light, IR radiation emitted from radiation emitter  202  will not interfere with the ALS function. 
     It is further to be understood that, in some embodiments, radiation detector  204  may also be capable of detecting ambient light so as to enhance an ALS performance of sensing device  200 . For example, radiation detector  204  may have both radiation detecting sensors and ambient light detecting sensors incorporated therein. In this aspect, ambient light detectors  230  and  231  can be used to detect the wide angle off-axis ambient light rays and the additional ambient light sensor incorporated within radiation detector  204  can detect rays within the viewing angle of the proximity sensing components (e.g., rays less than about 20 degrees off-axis) such that both ambient light rays within and outside of the collimated optics of sensing device  200  can be detected. 
     Returning briefly to the overall assembly of each of the ALS and proximity sensing components within sensing device  200 , in some embodiments, radiation emitter  202  and ambient light detector  230  may be mounted or formed within a portion of a substrate  212  within a first compartment  206  formed over substrate  212 . Radiation detector  204  may be mounted or formed within a portion of substrate  212  within a second compartment  208 . In one embodiment, substrate  212  is a printed circuit board (PCB) having traces, wire bond pads and vias disposed thereon or therein to facilitate transfer of electrical signals between radiation emitter  202 , radiation detector  204  and ambient light detectors  230 ,  231  and the electronic device within which sensing device  200  is implemented. Radiation emitter  202  may also be electrically coupled to proximity sensor circuitry  244  and radiation detector  204  may be electrically coupled to proximity sensor circuitry  240 . In addition, ambient light detector  230  may be electrically coupled to ALS circuitry  242  and ambient light detector  231  may be electrically coupled to ALS circuitry  243 . The circuitry may be signal processing circuitry that allows signals associated with the radiation emitter  202 , ambient light detectors  230 ,  231  and radiation detector  204  to be used by the electronic device to modify its operation (e.g., turn a display screen off). 
     The first and second compartments  206 ,  208  may be formed on opposing sides of a mid wall  210 . Mid wall  210  extends from substrate  212  and prevents cross talk between radiation emitter  202  and radiation detector  204 . Cross talk refers to an occurrence in which stray light from an emitter is detected by the detector thereby causing an undesired false signal mimicking a true proximity or object detection signal. Mid wall  210  may therefore be made of any type of material capable of blocking emitter stray signals from the detector, for example, a ceramic, a metal, a polyimide or other similar material opaque to IR radiation. 
     Sensing device  200  may further include optical element  218  and optical element  220 . Optical elements  218 ,  220  may be lenses fitted within openings  214 ,  216  formed within a top wall of each of compartments  206 ,  208 . Optical element  218  is positioned over radiation emitter  202  such that light emitted from radiation emitter  202  passes through optical element  218  to the ambient environment. Optical element  218  may further be positioned over ambient light detector  230  such that ambient or visible light from the outside environment can pass through optical element  218  to ambient light detector  230 . Optical element  220  is positioned over radiation detector  204  such that radiation from emitter  202 , which is reflected off a nearby object, can pass through optical element  220  to radiation detector  204 . Optical element  220  may further be positioned over ambient light detector  231  such that ambient or visible light from the outside environment can pass through optical element  220  to ambient light detector  231 . Each optical element  218 ,  220  may be configured to transmit and refract the incoming or outgoing light beams in the desired direction. For example, in some embodiments, optical elements  218 ,  220  may be drum lenses which can concentrate the transmitted light and therefore increase the amount of light focused at the nearby object or radiation detector  204 . This is particularly advantageous in the case of proximity detection because it can increase proximity detection distances. It is to be understood, however, that although exemplary optical elements are described herein, such features are optional and may be omitted in some embodiments. 
     In some embodiments, a window  222  may further be positioned over radiation emitter  202 , radiation detector  204  and ambient light detectors  230 ,  231 . Window  222  may be formed from a translucent or semi-translucent material such that it does not substantially modify the optical characteristics of sensing device  200 . Window  222  may be part of sensing device  200  or formed as part of the portable electronic device in which sensing device  200  is implemented. 
     Returning now to the viewing angles of ambient light detectors  230  and  231 , such viewing angles may be better understood by comparing the viewing angles of ambient light detectors  230  and  231  to radiation emitter  202  and radiation detector  204 , respectively. Such a comparison is illustrated in  FIG. 2C . In particular,  FIG. 2C  illustrates the wider viewing angle of ambient light detector  230  and ambient light detector  231 . As previously discussed, in the case of ALS, it is desirable for ambient light detectors  230  and  231  to be able to sense or detect incoming light coming from all different directions. In other words, it is desirable for ambient light sensors  230  and  231  to have a wider viewing angle than radiation emitter  202  and radiation detector  204 . 
     Since ambient light detector  230  is positioned around radiation emitter  202  as illustrated, it has a wider viewing angle  252  than that of radiation emitter  202  as illustrated by angle (Δ′). For example, in some cases, the ambient light detector viewing angle  252  may be from about 20 degrees to about 45 degrees. In such cases, angle (Δ′) may be from about 0 degrees to about 25 degrees, for example, from about 10 to about 20 degrees or about 15 degrees. In other words, the ambient light detector viewing angle  252  is anywhere from 0 to about 25 degrees greater than that of radiation emitter viewing angle  250 , and therefore ambient light detector  230  can detect light rays having an off-axis angle anywhere from 0 to 25 degrees outside of a FOV of radiation emitter  202 .  FIG. 2D  illustrates the FOV  260 A and  260 B of ambient light detector  230 , in comparison to the FOV  262  of radiation emitter  202 , which have been omitted from  FIG. 2C  for purposes of clarity. 
     In addition, ambient light detector  231  has a wider viewing angle  258  with respect to East off-axis rays than that of radiation detector  204  as illustrated by angle (Δ″). For example, in some cases, the ambient light detector viewing angle  258  may be from about 20 degrees to about 45 degrees, with respect to optical axis  256 . In such cases, angle (Δ″) may be from about 0 degrees to about 25 degrees, for example, from about 10 to about 20 degrees or about 15 degrees. In other words, the ambient light detector viewing angle  258  is anywhere from 0 to about 25 degrees greater in the East direction than that of radiation detector viewing angle  254  (which is typically less than about 20 degrees), and therefore ambient light detector  231  can detect light rays having an off-axis angle anywhere from 0 to 25 degrees outside of a FOV of radiation detector  204 .  FIG. 2D  illustrates the FOV  261  of ambient light detector  231 , in comparison to the FOV  263  of radiation detector  204 , which have been omitted from  FIG. 2C  for purposes of clarity. 
       FIG. 3  is a cross-sectional side view of another embodiment of a sensing device. Sensing device  300  is substantially similar to sensing devices  100  and  200  except that in this embodiment, an ambient light detector is incorporated into both the radiation emitter and the radiation detector. In particular, sensing device  300  includes a radiation emitter/ambient light detector module  302  within first compartment  306  and a radiation detector/ambient light detector module  304  within second compartment  308 . The radiation emitter/ambient light detector module  302  may generate and emit radiation in, for example, the infrared (IR) bands. For example, radiation emitter/ambient light detector module  302  may include a semiconductor radiation source such as a light emitting diode (LED). Radiation emitter/ambient light detector module  302  may also include an ambient light detecting source such as a photodiode or other type of photodetector that is capable of detecting ambient light (e.g., light within a visible wavelength). Alternatively, or additionally, the radiation emitter/ambient light detector module  302  may include an LED which can operate as both a light emitter and a photodetector. Since both the radiation emitter and the ambient light detector are implemented within a single radiation emitter/ambient light detector module  302 , they will have substantially the same viewing angle and FOV. This means that due to the collimated optics of sensing device  300 , the ambient light detector viewing angle  352  may be within a relatively narrow angle range of from about 0 degrees to about 20 degrees with respect to optical axis  326 . 
     To compensate for this narrower viewing angle, a second ambient light detecting functionality may be provided by the radiation detector/ambient light detector module  304  within second compartment  308 . The radiation detector/ambient light detector  304  may be configured to detect changes in the intensity of radiation emitted from radiation emitter/ambient light detector module  302  as well as ambient light outside of sensing device  300 . In this aspect, radiation detector/ambient light detector module  304  may provide a proximity sensing function as well as an ambient light sensing function. Representatively, radiation detector/ambient light detector module  304  may include one or more photodiodes or other type of photodetectors capable of sensing and converting IR radiation into a current or voltage that can then be processed by the device within which it is implemented, as well as one or more photodiodes capable of sensing and converting ambient light into a current or voltage for processing by the device. Since both the radiation detector and the ambient light detector are implemented within a single radiation detector/ambient light detector module  304 , they will have substantially the same viewing angle and FOV. The ambient light detector viewing angle  354  of radiation detector/ambient light detector module  304  may therefore be similar to viewing angle  352  (e.g., from about 0 degrees to about 20 degrees with respect to optical axis  356 ). Nevertheless, since ambient light detection occurs within two different sides of sensing device  300 , it is believed that a sufficient amount of light may be captured for proper ALS function. In addition, where detection of off-axis rays having an angle greater than about 20 degrees with respect to an optical axis is desired, any of the previously discussed ambient light detector configurations may be implemented within sensing device  300 . For example, an additional ambient light detector bordering radiation emitter/ambient light detector module  302  and radiation detector/ambient light detector module  304  as previously discussed may be provided to facilitate detection of light rays off-axis by more than 20 degrees. 
     Returning briefly to the overall assembly of each of the ALS and proximity sensing components within sensing device  300 , in some embodiments, radiation emitter/ambient light detector module  302  may be mounted or formed within a portion of a substrate  312  within a first compartment  306  formed over substrate  312 . Radiation detector/ambient light detector module  304  may be mounted or formed within a portion of substrate  312  within a second compartment  308 . In one embodiment, substrate  312  is a printed circuit board (PCB) having traces, wire bond pads and/or vias disposed thereon or therein to facilitate transfer of electrical signals between radiation emitter/ambient light detector module  302  and radiation detector/ambient light detector  304  and the electronic device within which sensing device  300  is implemented. Radiation emitter/ambient light detector module  302  may also be electrically coupled to proximity sensor circuitry  344  and ALS circuitry  346 . Radiation detector/ambient light detector module  304  may be electrically coupled to proximity sensor circuitry  340  and ALS circuitry  342 . The circuitry may be signal processing circuitry that allows signals associated with the radiation emitter/ambient light detector  302  and the radiation detector/ambient light detector  304  to be used by the electronic device to modify its operation (e.g., turn a display screen off). 
     The first and second compartments  306 ,  308  may be formed on opposing sides of a mid wall  310 . Mid wall  310  extends from substrate  312  and prevents cross talk between radiation emitter/ambient light detector  302  and the radiation detector/ambient light detector  304 . Mid wall  310  may therefore be made of any type of material capable of blocking emitter stray signals from the detector, for example, a ceramic, a metal, a polyimide or other similar material opaque to IR radiation. 
     Sensing device  300  may further include optical element  318  and optical element  320 . Optical elements  318 ,  320  may be lenses fitted within openings  314 ,  316  formed within a top wall of each of compartments  306 ,  308 . Optical element  318  is positioned over radiation emitter/ambient light detector module  302  such that light emitted from radiation emitter/ambient light detector  302  passes through optical element  318  to the ambient environment and ambient light can pass from the ambient environment to radiation emitter/ambient light detector module  302 . Optical element  320  is positioned over radiation detector/ambient light detector module  304  such that radiation from radiation emitter/ambient light detector module  302 , which is reflected off a nearby object, can pass through optical element  320  to radiation detector/ambient light detector module  304  as can light from the ambient environment. Each optical element  318 ,  320  may be configured to transmit and refract the incoming or outgoing light beams in the desired direction. For example, in some embodiments, optical elements  318 ,  320  may be drum lenses which can concentrate the transmitted light and therefore increase the amount of light focused at the nearby object or radiation detector/ambient light detector  304 . This is particularly advantageous in the case of proximity detection because it can increase proximity detection distances. It is to be understood, however, that although exemplary optical elements are described herein, such features are optional and may be omitted in some embodiments. 
     In some embodiments, a window  322  may further be positioned over radiation emitter/ambient light detector module  302  and radiation detector/ambient light detector module  304 . Window  322  may be formed from a translucent or semi-translucent material such that it does not substantially modify the optical characteristics of sensing device  300 . Window  322  may be part of sensing device  300  or formed as part of the portable electronic device in which sensing device  300  is implemented. 
     Turning now to  FIG. 4 , this figure depicts an example embodiment of a portable handheld device  400  having a sensing device  412  implemented therein. Sensing device  412  may be any of the previously discussed sensing devices  100 ,  200 ,  300 . In this illustration, a near end user is holding the device  400  in their hand. Sensing device  412  may be positioned within an outer casing of handheld device  400  near a front face of handheld device  400  so that it can sense a proximity of a user when the user draws the phone toward their face. It is contemplated, however, that sensing device  412  may be associated with other portions of handheld device  400 , for example, a bottom, a top or a side portion of handheld device  400 . In one embodiment, opening  402  may be associated with an earpiece receiver  404 . In some embodiments, opening  402  may be configured to accommodate both an earpiece receiver  404  and another component, such as an audio proximity sensing device. 
     Handheld device  400  may include various capabilities to enable the user to access features involving, for example, calls, text messages, voicemail, e-mail, the Internet, scheduling, photos, and music as shown on the touch screen display  406 . In addition, handheld device  400  may include a microphone  408  and speakerphone speaker  410  to allow for input and/or output of audio signals to and from handheld device  400 . When the user holds the handheld device  400  to their head during a call in, for example, the device handset mode, the earpiece receiver speaker  404  (which may be located at a top end portion of the handheld device  400 ) may be positioned against the user&#39;s ear. In that case, the sensing device  412  is situated in the general direction of the user. An emitter within sensing device  412  emits, for example, an IR light beam through the front face (which is formed by a transparent window or casing). The light beam is then reflected off of the user, and a based on the intensity of the beam, handheld device  400  can determine a proximity of the user, and for example, disable the touch screen display  406  when the device  400  is determined to be close to the user&#39;s face. In addition, when sensing device  412  detects a relatively low ambient light intensity level, the display lighting may be reduced, for example, to conserve battery power. 
     It is to be understood that although a handheld device such as an iPhone® from Apple Computer, Inc. of Cupertino, Calif., is illustrated in  FIG. 4 , any of the sensing devices disclosed herein may be implemented within any number of electronic devices that could benefit from a light and proximity sensing device. For example, sensing device  412  may be implemented within a tablet computer, a notebook computer or other portable computing device. In still further embodiments, sensing device  412  may be implemented within a digital media player, such as a portable music and/or video media player, entertainment systems or personal digital assistants (PDAs), or general purpose computer systems, or special purpose computer systems, or an embedded device within another device, or cellular telephones which do not include media players, or devices which combine aspects or functions of these devices (e.g., a media player, such as an iPod®, combined with a PDA, an entertainment system, and a cellular telephone in one portable device). 
       FIG. 5  shows a block diagram of an embodiment of a wireless device  500  within which sensing device  412  (e.g., sensing devices  100 ,  200 ,  300 ) may be implemented. In the illustrated embodiment, wireless device  500  is a wireless communication device. The wireless device  500  may be included in the device shown in  FIG. 4 , although alternative embodiments of handheld device  400  may include more or fewer components than the wireless device  500 . 
     Wireless device  500  may include an antenna system  502 . Wireless device  500  may also include a radio frequency (RF) transceiver  504 , coupled to the antenna system  502 , to transmit and/or receive voice, digital data and/or media signals through antenna system  502 . 
     A digital processing system  506  may further be provided to control the digital RF transceiver and to manage the voice, digital data and/or media signals. Digital processing system  506  may be a general purpose processing device, such as a microprocessor or controller for example. Digital processing system  506  may also be a special purpose processing device, such as an ASIC (application specific integrated circuit), FPGA (field-programmable gate array) or DSP (digital signal processor). Digital processing system  506  may also include other devices to interface with other components of wireless device  500 . For example, digital processing system  506  may include analog-to-digital and digital-to-analog converters to interface with other components of wireless device  500 . 
     A storage device  508 , coupled to the digital processing system, may further be included in wireless device  500 . Storage device  508  may store data and/or operating programs for the wireless device  500 . Storage device  508  may be, for example, any type of solid-state or magnetic memory device. 
     One or more input devices  510 , coupled to the digital processing system  506 , to accept user inputs (e.g., telephone numbers, names, addresses, media selections, etc.) or output information to a far end user may further be provided. Exemplary input devices may be, for example, one or more of a keypad, a touchpad, a touch screen, a pointing device in combination with a display device or similar input device. 
     Display device  518  may be coupled to the digital processing system  506 , to display information such as messages, telephone call information, contact information, pictures, movies and/or titles or other indicators of media being selected via the input device  510 . Display device  518  may be, for example, an LCD display device. In one embodiment, display device  518  and input device  510  may be integrated together in the same device (e.g., a touch screen LCD such as a multi-touch input panel which is integrated with a display device, such as an LCD display device). It will be appreciated that the wireless device  500  may include multiple displays. 
     Battery  514  may further be provided to supply operating power to components of the system including digital RF transceiver  504 , digital processing system  506 , storage device  508 , input device  510 , audio transducer  516 , proximity and/or ALS sensor(s)  522  (e.g., sensing devices  100 ,  200 ,  300 ), and display device  518 . Battery  514  may be, for example, a rechargeable or non-rechargeable lithium or nickel metal hydride battery. Wireless device  500  may also include audio transducers  516 , which may include one or more speakers, receivers and at least one microphone. 
     Proximity and/or ALS sensor(s)  522  may be coupled to the digital processing system  506 . The proximity and/or ALS sensor(s)  522  may include, for example, one or more of a light and/or proximity sensor. Based on the data acquired by the proximity and/or ALS sensor(s)  522 , various responses may be performed automatically by the digital processing system, such as, for example, activating or deactivating the backlight, changing a setting of the input device  510  (e.g., switching between processing or not processing, as an intentional user input, any input data from an input device), and other responses and combinations thereof. It is noted that other types of sensors may also be included in wireless device  500 , such as an accelerometer, touch input panel, ambient noise sensor, temperature sensor, gyroscope, a hinge detector, a position determination device, an orientation determination device, a motion sensor, a sound sensor, a radio frequency electromagnetic wave sensor, and other types of sensors and combinations thereof. 
     Returning to proximity and/or ALS sensor(s)  522 , proximity and/or ALS sensor(s)  522  may include one or more ALS or proximity sensors (e.g., sensing devices  100 ,  200 ,  300 ) which provide data relating to light. The data can be analyzed by digital processing system  506  to determine whether or not to adjust one or more settings of wireless device  500 . Ambient light level data may be provided by an ambient light sensor feature of the sensing device, which indicates the level of light intensity surrounding that sensor. For example, ambient light differential data may be obtained from two or more ambient light sensors which are disposed at different positions on the device. For example, one ambient light sensor may be on one side of the device, and another ambient light sensor may be on another side of the device. A difference in the light intensity levels may be determined by comparing the data from these two ambient light sensors on two different sides or surfaces of the device. 
     There are a variety of possible uses of a light sensor. For example, the light sensor may be used with a proximity sensor to determine when a device is placed in a pocket to cause the device to be set in vibrate mode only or vibrate mode with audible ringing. In another example, in response to a light sensor determining that the ambient light is very low, and optionally in response to a user having set the device to visibly light up to show an incoming call when the ambient light is very low, the device may automatically be put in a “light ring” mode when it is dark so that instead of an audible ring from the device, the display flashes visibly (e.g., by repeatedly turning on and off the backlight) to indicate an incoming call. Another exemplary use of a light sensor involves using it as an alarm indicating that a dark room (or environment) has become brighter (e.g., the sun has risen or a door to a darkened room is opened to let light into the room). A light sensor may also be used to cause a device to automatically act as a source of light (e.g., as a flashlight, in effect) upon sensing a low ambient light level. 
     While certain embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that the invention is not limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those of ordinary skill in the art. For example, although portable handle held devices are described herein, it is contemplated that sensing device may be implemented in other types of devices including, but not limited to, a desk top computer, television or the like. The description is thus to be regarded as illustrative instead of limiting.

Metadata:
Filing Date: 20130306
Publication Date: 20160322
Grant Date: 20160322
Priority Date: 20130306
Inventors: LAND BRIAN R.
RUH RICHARD
HOTELLING STEVEN P.
Assignee: APPLE INC
CPC Classifications: [{"code": "G01V8/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S17/86", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01S17/86", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01S7/481", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J1/4204", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01S17/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S17/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J1/4204", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01V8/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/481", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S17/023", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01S17/026", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01S7/481", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 50236274