BACKGROUND

Optoelectronic proximity sensors typically are configured to measure the distances of objects (e.g., a finger, hand, or ear) in close proximity. Optoelectronic proximity sensors operate by directing light onto an object, and collecting the light reflected from the object. Often the intensity of the collected light is related (e.g., proportional) to the distance between the object and the optoelectronic proximity sensor. However, objects exhibit a range of surface reflectivity. For example, in instances where the object is a finger, hand or ear, the surface reflectivity of the object can depend strongly on skin pigmentation. Accordingly, optoelectronic proximity sensors operable to measure proximity independent of object surface reflectivity are needed.

SUMMARY

This disclosure describes optoelectronic devices operable to measure proximity substantially independently of object surface reflectivity and methods for operating the same. The optoelectronic devices described in this disclosure have an asymmetric field overlap. The asymmetric field overlap permits proximity measurements substantially independent of object surface reflectivity.

In one aspect, for example, an optoelectronic device operable to measure proximity includes a first light-emitting assembly, a second light-emitting assembly, and a light-sensitive assembly. The first light-emitting assembly is operable to emit light onto an object at a position proximal to the optoelectronic device within a first field-of-illumination. The first field-of-illumination is characterized by a first field-of-illumination angle and first field-of-illumination axis. The second light-emitting assembly being operable to emit light onto the object at the position proximal to the optoelectronic device and within a second field-of-illumination. The second field-of-illumination is characterized by a second field-of-illumination angle and a second filed-of-illumination axis.

The light-sensitive assembly is operable to collect light over a field-of-view. The field-of-view is characterized by a field-of-view angle and field-of-view axis. The light-sensitive assembly is operable to convert light emitted by the first light-emitting assembly reflected from the object into a first signal. Moreover, the light-sensitive assembly is operable to convert light emitted by the second light-emitting assembly reflected from the object into a second signal. The light-sensitive assembly is disposed from the first light-emitting assembly by a first pitch, and the light-sensitive assembly is disposed from the second light-emitting assembly by a second pitch.

In some instances, the first light-emitting assembly, the second light-emitting assembly, and/or the light-sensitive assembly includes an optical assembly. The optical assembly can include an anti-reflection coating.

In some instances, the first light-emitting assembly and the second light-emitting assembly includes a light-emitting component. The light-emitting component can include a light-emitting diode and/or a laser diode.

In some instances, the light-sensitive assembly includes a light-sensitive component. The light-sensitive component can include a photodiode, charge-coupled device, and/or a complementary metal-oxide-semiconductor.

In some instances, the first pitch is substantially unequal to the second pitch, and the first field-of-illumination angle is substantially unequal to the second field-of-illumination angle. For example, the second pitch is between two and ten times the length of the first pitch, and the first field-of-illumination angle is between two and ten times the angle of the second field-of-illumination angle.

In some instances, the asymmetric field overlap is attained by a configuration including up to all but one of the following:the first pitch is substantially equal to the second pitchthe first field-of-illumination angle is substantially equal to the second illumination anglethe first field-of-illumination axis is substantially parallel to the second field-of-illumination axisthe field-of-view angle is substantially equal to the first field-of-illumination anglethe field-of-view angle is substantially equal to the second field-of-illumination anglethe field-of-view axis is substantially parallel to the first field-of-illumination axisthe field-of-view axis is substantially parallel to the second field-of-illumination axis.

In some implementations, the first pitch is unequal to the second pitch. In some cases, the optoelectronic device includes an optical element over only one of the first light-sensitive assembly or the second light-sensitive assembly, wherein the presence of the optical element contributes to the asymmetric field overlap. In some instances, the optoelectronic device includes a respective optical element over each of the first light-sensitive assembly and the second light-sensitive assembly, wherein a difference in the optical element over the first light-sensitive assembly and the optical element over the second light-sensitive assembly contributes to the asymmetric field overlap.

In some instances, two or more approaches described here for attaining an asymmetric overlap can be used in combination.

In some instances, the optoelectronic device includes a processor and a non-transitory computer-readable medium comprising instructions stored thereon, that when executed on the processor, perform operations including:emitting light from the first light-emitting assembly over the first field-of-illumination and onto the object at the position proximal to the optoelectronic device and within the first field-of-illuminationcollecting light emitted by the first light-emitting assembly and reflected from the object with the light-sensitive assemblyconverting the light emitted by the first light-emitting assembly, reflected from the object, and collected by the light-sensitive assembly into the first signalemitting light from the second light-emitting assembly over the second field-of-illumination and onto the object at the position proximal to the optoelectronic device and within the second field-of-illuminationcollecting light emitted by the second light-emitting assembly and reflected from the object with the light-sensitive assemblyconverting the light emitted by the second light-emitting assembly, reflected from the object, and collected by the light-sensitive assembly into the second signaldetermining a signal ratio by normalizing the first signal by the second signalrecalling a threshold signal ratio from the non-transitory computer-readable medium, the threshold signal ratio being associated with a threshold proximity value relative to the optoelectronic devicecomparing the threshold signal ratio to the signal ratioassociating the threshold proximity value with the position of the object proximal to the optoelectronic device for signal ratios equal to or greater than the threshold signal ratio.

In another aspect, for example, a method for operating the optoelectronic device includes:emitting light from a first light-emitting assembly over a first field-of-illumination and onto an object at a position proximal to the optoelectronic device and within the first field-of-illuminationcollecting light emitted by the first light-emitting assembly and reflected from the object with a light-sensitive assemblyconverting the light emitted by the first light-emitting assembly, reflected from the object, and collected by the light-sensitive assembly into a first signalemitting light from a second light-emitting assembly over a second field-of-illumination and onto the object at the position proximal to the optoelectronic device and within a second field-of-illuminationcollecting light emitted by the second light-emitting assembly and reflected from the object with the light-sensitive assemblyconverting the light emitted by the second light-emitting assembly, reflected from the object, and collected by the light-sensitive assembly into a second signaldetermining a signal ratio by normalizing the first signal by the second signalrecalling a threshold signal ratio from a non-transitory computer-readable medium, the threshold signal ratio being associated with a threshold proximity value relative to the optoelectronic devicecomparing the threshold signal ratio to the signal ratioassociating the threshold proximity value with the position of the object proximal to the optoelectronic device for signal ratios equal to or greater than the threshold signal ratio.

In another aspect, for example, an optoelectronic device operable to measure proximity includes a light-emitting assembly, a first light-sensitive assembly, and a second light-sensitive assembly. The light-emitting assembly is operable to emit light onto an object at a position proximal to the optoelectronic device within a field-of-illumination. The field-of-illumination is characterized by a field-of-illumination angle and an illumination axis.

The first light-sensitive assembly is operable to collect light over a first field-of-view. The first field-of-view is characterized by a first field-of-view angle and first view axis. The first light-sensitive assembly is operable to convert light emitted by the light-emitting assembly reflected from the object into a first signal.

The second light-sensitive assembly is operable to collect light over a second field-of-view. The second field-of-view is characterized by a second field-of-view angle and second view axis. The second light-sensitive assembly is operable to convert light emitted by the light-emitting assembly reflected from the object into a second signal. Moreover, the first light-sensitive assembly is disposed from the light-emitting assembly by a first pitch, and the second light-sensitive assembly is disposed from the light-emitting assembly by a second pitch.

In some instances, the light-emitting assembly, the first light-sensitive assembly, and/or the second light-sensitive assembly includes an optical assembly. The optical assembly can include an anti-reflection coating.

In some instances, the light-emitting assembly includes a light-emitting component. The light-emitting component can include a light-emitting diode and/or a laser diode.

In some instances, the first light-sensitive assembly and the second light-sensitive assembly each include a light-sensitive component. The light-sensitive component can include a photodiode, a charge-coupled device, and/or a complementary metal-oxide-semiconductor.

In some instances, the first pitch is substantially unequal to the second pitch, and the first field-of-view angle is substantially unequal to the second field-of-view angle. For example, the second pitch is between two and ten times the length of the first pitch, and the first field-of-view angle is between two and ten times the angle of the second field-of-view angle.

In some instances, the asymmetric field overlap is attained by any configuration including up to all but one of the following:the first pitch is substantially equal to the second pitchthe first field-of-view angle is substantially equal to the second field-of-view anglethe first field-of-view axis is substantially parallel to the second field-of-view axisthe field-of-illumination angle is substantially equal to the first field-of-view anglethe field-of-illumination angle is substantially equal to the second field-of-view anglethe field-of-illumination axis is substantially parallel to the first field-of-view axisthe field-of-illumination axis is substantially parallel to the second field-of-view axis.

In some instances, the optoelectronic device can include a processor, and can include a non-transitory computer-readable medium comprising instructions stored thereon, that when executed on the processor, perform operations including:emitting light from the light-emitting assembly over the field-of-illumination and onto the object at the position proximal to the optoelectronic device and within the field-of-illuminationcollecting light emitted by the light-emitting assembly and reflected from the object with the first light-sensitive assemblyconverting the light emitted by the light-emitting assembly, reflected from the object, and collected by the first light-sensitive assembly into the first signalcollecting light emitted by the light-emitting assembly and reflected from the object with the second light-sensitive assemblyconverting the light emitted by the light-emitting assembly, reflected from the object, and collected by the second light-sensitive assembly into the second signaldetermining a signal ratio by normalizing the first signal by the second signalrecalling a threshold signal ratio from the non-transitory computer-readable medium, the threshold signal ratio being associated with a threshold proximity value relative to the optoelectronic devicecomparing the threshold signal ratio to the signal ratioassociating the threshold proximity value with the position of the object proximal to the optoelectronic device for signal ratios equal to or greater than the threshold signal ratio.

In another aspect, for example, a method for operating the optoelectronic device includes:emitting light from a light-emitting assembly over a field-of-illumination and onto an object at a position proximal to the optoelectronic device and within the field-of-illuminationcollecting light emitted by the light-emitting assembly and reflected from the object with a first light-sensitive assemblyconverting the light emitted by the light-emitting assembly, reflected from the object, and collected by the first light-sensitive assembly into a first signalcollecting light emitted by the light-emitting assembly and reflected from the object with a second light-sensitive assemblyconverting the light emitted by the light-emitting assembly, reflected from the object, and collected by the second light-sensitive assembly into a second signaldetermining a signal ratio by normalizing the first signal by the second signalrecalling a threshold signal ratio from a non-transitory computer-readable medium, the threshold signal ratio being associated with a threshold proximity value relative to the optoelectronic devicecomparing the threshold signal ratio to the signal ratioassociating the threshold proximity value with the position of the object proximal to the optoelectronic device for signal ratios equal to or greater than the threshold signal ratio.

In some instances, the method further includes the operation of activating an auxiliary function, the auxiliary function being implemented on a host device into which the optoelectronic device is incorporated.

In some instances, the auxiliary function includes activating a display screen incorporated into the host device.

In some instances, the auxiliary function includes regulating power to a component incorporated into the host device.

In some instances, the position of the object proximal to the optoelectronic device is collected over time and stored in the non-transitory computer-readable medium as three-dimensional data.

In some instances, the three-dimensional data includes velocity and/or acceleration data of the object.

Other aspects, features and advantages will be apparent from the following detailed description, the accompanying drawings, and the claims.

