Abstract:
The present disclosure describes optoelectronic modules with low- and high-power illumination modes for distance measurements and/or multi-dimensional imaging. Various implementations are described that include low- and high-power emitters. In some instances, a low-power mode may be used to monitor a scene where object movement can activate a high-power mode. In such instances, power reduction may be achieved.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to optoelectronic modules having low- and high-power illumination modes for distance measurements and/or multi-dimensional imaging such as 3D imaging and/or depth-mapping. 
       BACKGROUND 
       [0002]    Optoelectronic modules configured to acquire distances of objects in a three-dimensional scene typically employ an illumination source and an imaging assembly. The imaging assembly, including an optical assembly and pixel array, captures scene-induced modifications to light projected by the illumination source. For example, optoelectronic modules utilizing time-of-flight (TOF) technology typically include a modulated illumination/light source, optical assembly, and array of demodulation pixels. The modulated light is incident onto an object or objects in a scene at various distances from the optoelectronic module. The light is reflected from objects in a scene and is focused by an optical assembly onto a pixel array. The reflected light undergoes a phase shift; the phase shift is detected by pixels in the pixel array, wherein signals are generated that are then correlated to distances in the scene. 
         [0003]    Typically, the modulated light source employed in the optoelectronic modules described above homogeneously illuminate a scene within a given field of view which is a particular advantage for high-resolution pixel arrays where the homogeneous illumination may enable the acquisition of high-resolution distance data. Homogenous illumination, however, consumes much power. Further, the aforementioned optoelectronic modules can be used in a number of applications, in particular in mobile applications (i.e., where a mobile, limited power source is required). Accordingly, optoelectronic modules with reduced power consumption are highly desirable. 
       SUMMARY 
       [0004]    This disclosure describes optoelectronic modules having low- and high-power illumination modes for distance measurements and/or multi-dimensional imaging for reduced power consumption. 
         [0005]    For example, in one aspect, the disclosure describes an optoelectronic module that includes a substrate (such as a printed circuit board) on which are integrated an imaging assembly, a first illumination assembly, and a second illumination assembly. The imaging assembly includes a pixel array (such as an array of complementary metal-oxide-semiconductor and/or charge-coupled pixels) operable to detect one or more wavelengths of light. The imaging assembly further includes an imaging assembly spacer, and an imaging optical assembly. The pixel array is mounted to the substrate and the imaging assembly spacer is disposed in between the imaging optical assembly and the substrate, where the optical assembly is aligned with the pixel array. The first illumination assembly includes a first emitter (such as a light-emitting diode and/or a vertical-cavity surface-emitting laser) operable to emit a first emitted light of one or more wavelengths (such as light corresponding to the infrared spectrum), a first emitter spacer, and a first optical assembly operable to allow a first emission of the first emitted light to pass. Further the first emitter is mounted to the substrate and the first emitter spacer is disposed in between the first optical assembly and the substrate, and the first optical assembly is aligned with the first emitter. In addition, the second illumination assembly includes a second emitter operable to emit a second emitted light of one or more wavelengths, a second emitter spacer, and a second optical assembly operable to allow a second emission of the second emitted light to pass. Further, the second emitter is mounted to the substrate and the second emitter spacer is disposed in between the second optical assembly and the substrate, and the second optical assembly is aligned with the second emitter. 
         [0006]    According to another aspect, the first illumination assembly and the second illumination assembly are arranged to generate first and second respective illuminations with different powers from one another. 
         [0007]    According to yet another aspect, the optoelectronic module is operable to determine a distance to an object based on reflections of light from the object detected by the pixel array of the imaging assembly, where a change in position of the object detected by the module activates emission of light by the second emitter. 
         [0008]    According to still yet another aspect, a change in position of the object detected by the optoelectronic module causes the first emitter to cease illumination. 
         [0009]    Various implementations can provide one or more of the following advantages. For example, some implementations can help reduce power consumed by the optoelectronic module when the module collects distance data via time-of-flight. Still other implementations can help reduce power consumed by the optoelectronic module when the module collects distance data via stereo-imaging. 
         [0010]    Other aspects, features and advantages will be readily apparent from the following detailed description, the accompanying drawings and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1A  depicts an example of an optoelectronic module having low- and high-power emitters operating in a low-power mode. 
           [0012]      FIG. 1B  depicts an example of an optoelectronic module having low- and high-power emitters operating in a high-power mode. 
           [0013]      FIG. 2A  depicts an example of an optoelectronic module having a hybrid low- and high-power emitter operating in low-power mode. 
           [0014]      FIG. 2B  depicts an example of an optoelectronic module having a hybrid low- and high-power emitter operating in high-power mode. 
           [0015]      FIG. 3A  depicts an example of an optoelectronic module including an autofocus assembly and having low- and high-power emitters operating in a low-power mode. 
           [0016]      FIG. 3B  depicts an example of an optoelectronic module including an autofocus assembly and having low- and high-power emitters and an autofocus assembly operating in a high-power mode. 
           [0017]      FIG. 4A  depicts an example of an optoelectronic module configured to capture stereo images and having low- and high-power emitters operating in a low-power mode. 
           [0018]      FIG. 4B  depicts an example of an optoelectronic module configured to capture stereo images and having low- and high-power emitters operating in a high-power mode. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]      FIG. 1A  depicts an example of an optoelectronic module  100  having low- and high-power emitters (which are examples of first and second emitters, respectively) operating in a low-power mode (which is an example of a first mode). The optoelectronic module  100  can include an imaging assembly  101 , a substrate  101 A (such as a printed circuit board (PCB)), an imaging assembly spacer  101 B, a low-power illumination assembly  104  (which is an example of a first illumination assembly), and a high-power illumination assembly  112  (which is an example of a second illumination assembly). The imaging assembly  101  can include a pixel array  102 , such as an array of demodulation pixels, mounted on a substrate  101 A, and an imaging optical assembly  103 . The imaging optical assembly  103  may include a plurality of lens elements, barrels, stops, apertures, and filters. The low-power illumination assembly  104  can include a low-power emitter  105  (which is an example of a first emitter) such as a light emitting diode, edge emitting laser (EEL), vertical-cavity surface-emitting laser (VCSEL), or VCSEL array, mounted on a substrate  101 A; a first emitter spacer  105 A; and a low-power optical assembly  107  (which is an example of a first optical assembly). In a low-power mode, the low-power emitter  105  emits a low-power emitted light  106  (which is an example of a first emitted light). The low-power emitted light  106  can be any wavelength or range of wavelengths of electromagnetic radiation (e.g. visible or non-visible radiation). For example, low-power emitted light  106  can be near-, mid-, or far-infrared radiation. Further the low-power emitted light  106  can be modulated. The low-power emitted light  106  is incident on the low-power optical assembly  107 . The low-power optical assembly  107  can be any one of, or combinations of, the following optical elements: a diffraction grating, a microlens array, a lens, a prism, a micro-prism array, a diffractive optical element or a plurality of any one of the aforementioned or their respective combinations. The low-power optical assembly  107  may further be composed of apertures, spacers, alignment features, and other components pertinent to its function. The low-power emitted light  106  incident on the low-power optical assembly  107  may produce a low-power emission  108  (which is an example of a first emission). 
         [0020]    The low-power emission  108  may produce at a first position  110 A a low-power illumination  109 A (which is an example of a first illumination at a first position) incident on an object at a first position  110 A in a scene. The object can be illuminated by the first low-power illumination  109 A when at a particular distance or range of distances (e.g., between a few centimeters and several or even tens of meters). The low-power emission  108  may further produce at a second position  110 B a low-power illumination  109 B (which is an example of a first illumination at a second position) on the object at a second position  110 B in the scene. Typically, the TOF module operating in high-power mode may consume tens of mW to tens of W. However, the TOF module in low-power mode may consume considerably less power (e.g., 2 to 100 times less than the high-power mode). The solid arrow in  FIG. 1A  illustrates movement of the object from the first position  110 A to the second position  110 B in the scene. The low-power emission  108  may encompass a first field-of-view (FOV). The first low-power illumination  109 A and second low-power illumination  109 B (which is an example of a first illumination at a second position) may take the form of a pattern of high-contrast features, for example, a discrete array of illuminated dots, lines, or other shapes, or combinations of the aforementioned features. The distance between the high-contrast features can be strongly correlated with the intended application of the optoelectronic module  100 ; generally, the distance between the features can be on the order of the dimension of the objects in the scene or smaller. For example, if the object is, e.g., a person at a distance of 3 m from the optoelectronic module, the distance between the high-contrast features can be 30-40 cm at the expected working distance. The distance between the high-contrast features could be less, however. For example, if the object is a hand at a distance of 0.5 m from the optoelectronic module, the distance between the high-contrast features can be 5-10 cm. In general, the power required to produce the low-power emission  108 , and subsequent low-power illuminations  109 A and  109 B, is considerably less than the power required to produce a homogenous illumination of the same intensity. 
         [0021]    Light reflected from an object at a first position  110 A is low-power reflected light  111 A (which is an example of a first reflected light at a first position). Light reflected from an object at a second position  110 B is low-power reflected light  111 B (which is an example of a first reflected light at a second position). The reflected light can be collected and processed by the imaging assembly  101 . For example, the first low-power reflected light  111 A can be imaged by an optical assembly  103  and focused onto the demodulation pixel array  102 , wherein a distant-dependent phase-shift can be determined and correlated with distance from the optoelectronic module  100  to the object at a first position  110 A. Similarly, at another instant in time for example, the second low-power reflected light  111 B can be correlated with distance to the object at a second position  110 B as described above. The detection of a distance or position change between the object at a first position  110 A and the object at a second position  110 B is associated with object movement. Generally, the aforementioned detection of movement of the object from the first position to the second position may activate a high-power mode (e.g., may activate the high-power illumination assembly  112 ). However, in other instances, an object entering the scene may also activate a high-power mode. 
         [0022]      FIG. 1B  depicts an example of an optoelectronic module including low- and high-power emitters operating in a high-power mode. The high-power illumination assembly  112  is composed of a high-power emitter  113  (which is an example of a second emitter) mounted on a substrate  101 A, a second emitter spacer  113 A, and a high-power optical assembly  115  (which is an example of a second optical assembly). In a high-power mode, the high-power emitter  113  emits a high-power emitted light  114  (which is an example of a second emitted light). The high-power emitted light  114  can be any wavelength or range of wavelengths of electromagnetic radiation e.g. visible or non-visible radiation. For example, the high-power emitted light  114  can be near-, mid-, or far-infrared radiation. Further the high-power emitted light  114  can be modulated. 
         [0023]    Still further, the high-power emitted light  114  is incident on the high-power optical assembly  115 . The high-power optical assembly  115  can be any one of, or combinations of, the following optical elements: a diffraction grating, a microlens array, a lens, a prism, a micro-prism array, a diffractive optical element or a plurality of anyone of the aforementioned or their respective combinations. The high-power optical assembly  115  may further be composed of apertures, spacers, alignment features, and other components pertinent to its function. The high-power emitted light  114  incident on the high-power optical assembly  115  produces a high-power emission  116  (which is an example of a second emission), wherein the high-power emission  116  can be in focus and produce a high-power illumination  117 C (which is an example of a second illumination) on an object or objects  110 C in a scene within a particular range of distances (for example, between a few centimeters and several or even tens of meters). The high-power emission  116  may encompass a second FOV. Further the second FOV may substantially encompass and can be substantially equivalent to the first FOV. Both the first and second FOV can be, for example, from about 20° to 140°, although in some instances the FOV may be smaller or greater depending on the intended application. 
         [0024]    The high-power illumination  117 C can be a homogenous (non-patterned, non-discrete) illumination. In other cases the high-power illumination  117 C may take the form of a dense pattern of high-contrast features, for example, a discrete array of illuminated dots, lines, or other shapes, or combinations of the aforementioned features. A high-power reflected light  118 C (which is an example of a second reflected light) can be reflected from an object or objects  110 C, and collected and processed by the imaging assembly  101 . For example, the high-power reflected light  118 C can be focused by the imaging optical assembly  103  onto the pixel array  102 , wherein a distant-dependent phase-shift can be determined and correlated with distance to an object or objects  110 C in the scene. The high-power reflected light  118 C, resulting from the high-power illumination  117 C, can be focused on a large fraction of the demodulation pixels in the pixel array, whereas the first and second low-power reflected light  111 A,  111 B, resulting from the first low-power illumination  109 A and second low-power illumination  109 B, are only focused on a fraction of demodulation pixels in the demodulation pixel array  102 . Consequently, higher resolution data can be obtained when the high-power illumination assembly  112  is employed. 
         [0025]    The optoelectronic module  100  described above may exhibit considerable reduction in power consumption. For example, the low-power illumination assembly  104  of the optoelectronic module  100  may illuminate an object or objects in a scene until an objected movement is detected; then the high-power illumination assembly  112  can be employed to obtain high-resolution distance data of the object/scene of interest. 
         [0026]    Still further, the optoelectronic module  100  described above may exhibit even greater reduction in power consumption when either the low-power emitter  105  and/or the high-power emitter  113  are operated in a pulsed mode. For example, the low-power emitter  105  may illuminate an object or objects in a scene for a short period (e.g., a fraction of a second to 1 second) and my cease to illuminate an object or objects in a scene for another short period (e.g., 1 second to a few seconds). This regime may continue until an object in the scene moves. Upon the detection of movement, as outlined above, the high-power mode (as previously described) can be activated. In other cases, the high-power emitter  113  can be operated in a similar manner. However, the high-power emitter  113  may illuminate and cease to illuminate the scene at considerably shorter periods (e.g., fractions of a second). The duration of the periods of illumination can be highly dependent on the nature of the objects (e.g., their speed of movement, position change). 
         [0027]    Although in the above examples object movement was detected by a phase shift in the modulated light reflected by an object in a scene, other variations to the optoelectronic module can be used to detect object movement. For example, the low-power illumination assembly  104  need not illuminate objects in a scene with modulated light. Objects can be illuminated with un-modulated light, wherein the intensity of light reflected from objects in a scene may change and be correlated with movement. Still further, other approaches can be used to detect movement such as via triangulation, i.e., where reflected light focused on a pixel array can be used to determine distance to an object (e.g., using the focal length of the imaging optical assembly  103 ; and the baseline distance between imaging assembly  101 , and low-power illumination assembly  104 ; and/or the baseline distance between imaging assembly  101 , and high-power illumination assembly  112 ). Hence movement over a given time interval can be determined. 
         [0028]    In previous examples, movement, distance/position change of an object in a scene may initiate a protocol wherein the low-power emitter  105  ceases to illuminate the scene and the high-power emitter  113  is activated. Upon activation of the high-power emitter  113  distance data of the object or objects in a scene can be determined (as described above). 
         [0029]    Still further, the imaging assembly  101  and/or the low-power illumination assembly  104  and/or the high-power illumination assembly  112  may include other optical filters, passives, other electrical components, and processors and other components (not shown) pertinent to the function of the optoelectronic module  100 . 
         [0030]      FIG. 2A  depicts an example of an optoelectronic module with a hybrid low- and high-power emitter operating in low-power mode. An optoelectronic module  200  includes an imaging assembly  201 , a substrate  201 A (such as a PCB), an imaging assembly spacer  201 B, and a hybrid illumination assembly  204 . The hybrid illumination assembly  204  includes a hybrid emitter  205  mounted on a substrate  201 A. The hybrid emitter  205  includes a low-power emitter region  206  (which is an example of a first emitter region) and a high-power emitter region  207  (which is an example of a second emitter region). The imaging assembly  201  can be further composed of a pixel array  202 , such as an array of demodulation pixels, mounted on a substrate  201 A, and an imaging optical assembly  203 . The imaging optical assembly  203  may include a plurality of lens elements, barrels, stops, apertures, and filters. The hybrid illumination assembly  204  can further include an emitter spacer  205 A and a hybrid optical assembly  208 . The hybrid optical assembly  208  includes a low-power optical assembly region  209  (which is an example of a first optical assembly region) and a high-power optical assembly region  210  (which is an example of a second optical assembly region). Further, the imaging assembly  201  may include an optical assembly, optical filters, a demodulation pixel array, passives and other electrical components (not shown) pertinent to the function of the optoelectronic module  200 . 
         [0031]    In a low-power mode, the low-power emitter region  206  emits a low-power emitted light  211  (which is an example of a first emitted light). The low-power emitted light  211  can be any wavelength or range of wavelengths of electromagnetic radiation e.g. visible or non-visible radiation. For example, low-power emitted light  211  can be near-, mid-, or far-infrared radiation. Further the low-power emitted light  211  can be modulated. The low-power emitted light  211  is incident on the low-power optical assembly region  209 . The low-power optical assembly region  209  can be any one of, or combinations of any one of the following optical elements: a diffraction grating, a microlens array, a lens, a prism, a micro-prism array, a diffractive optical element or a plurality of anyone of the aforementioned or their respective combinations. The low-power optical assembly region  209  may further be composed of apertures, spacers, alignment features, and other components pertinent to its function. The low-power emitted light  211  incident on the low-power optical assembly region  209  produces a low-power emission  212  (which is an example of a first emission), wherein the low-power emission  212  can be in focus and produce a first low-power illumination  213 A (which is an example of a first illumination at a first position) on an object at a first position  214 A within a particular range of distances (for example, between a few centimeters and several or even tens of meters). The low-power emission  212  may further produce a second low-power illumination  213 B (which is an example of a first illumination at a second position) on the object at a second position  214 B in the scene. The solid arrow in  FIG. 2A  illustrates movement of the object from the first position  214 A to the second position  214 B in the scene. The low-power emission  212  may encompass a first field-of-view (FOV). The first low-power illumination  213 A and second low-power illumination  213 B may take the form of a pattern of high-contrast features, for example, a discrete array of illuminated dots, lines, or other shapes, or combinations of the aforementioned. The distance between the high-contrast features can be strongly correlated with the intended application of the optoelectronic module  200 ; generally, the distance between the features can be on the order of the dimension of the objects in the scene or smaller. In general, the power required to produce the low-power emission  212 , and subsequent low-power illuminations  213 A and  213 B, is considerably less than the power required to produce a homogenous illumination of the same intensity. 
         [0032]    A first low-power reflected light  215 A (which is an example of a first reflected light at a first position) can be reflected from the object at a first position  214 A and the second low-power reflected light  215 B (which is an example of a first reflected light at a first position) can be reflected from the object at a second position  214 B. The reflected light can be collected and processed by the imaging assembly  201 . For example, the first low-power reflected light  215 A can be imaged by an optical assembly  203  and focused onto a demodulation pixel array  202 , wherein a distant-dependent phase-shift can be determined and correlated with distance from the optoelectronic module  200  to the object at a first position  214 A. Similarly, at another instant in time for example, the second low-power reflected light  215 B can be correlated with distance to the object at a second position  214 B as described above. The detection of a distance or position change between the object at a first position  214 A and the object at a second position  214 B is associated with object movement. Generally, the aforementioned detection of movement of the object from the first position to the second position may activate a high-power mode, e.g. may activate the high-power emitter region  207 . However, in other instances, an object entering the scene may also activate a high-power mode. 
         [0033]      FIG. 2B  depicts an example of an optoelectronic module with a hybrid low- and high-power emitter operating in high-power mode. In a high-power mode, the high-power emitter region  207  emits a high-power emitted light  216  (which is an example of a second emitted light). The high-power emitted light  216  can be any wavelength or range of wavelengths of electromagnetic radiation (e.g. visible or non-visible radiation). For example, high-power emitted light  216  can be near-, mid-, or far-infrared radiation. Further the high-power emitted light  216  can be modulated. The high-power emitted light  216  is incident on the high-power optical assembly region  210 . The high-power optical assembly region  210  can be any one of, or combinations of, the following optical elements: a diffraction grating, a microlens array, a lens, a prism, a micro-prism array, a diffractive optical element or a plurality of any one of the aforementioned or their respective combinations. The high-power optical assembly region  210  may further be composed of apertures, spacers, alignment features, and other components pertinent to its function. The high-power emitted light  216  incident on the high-power optical assembly region  210  produces a high-power emission  217  (which is an example of a second emission), wherein the high-power emission  217  can be in focus and produce a high-power illumination  218 C (which is an example of a second illumination) on an object or objects  214 C in a scene within a particular range of distances (for example, between a few centimeters and several or even tens of meters). The high-power emission  217  may encompass a second FOV. Further the second FOV may substantially encompass, and can be substantially equivalent to, the first FOV. Both the first and second FOV can be, for example, from about 20° to 140°, although they may be greater depending on the intended application. 
         [0034]    The high-power illumination  218 C can be a homogenous (non-patterned, non-discrete) illumination. In other cases the high-power illumination  218 C may take the form of a dense pattern of high-contrast features, for example, a discrete array of illuminated dots, lines, or other shapes, or combinations of the aforementioned features. A high-power reflected light  219 C (which is an example of a second reflected light) can be reflected from an object or objects  214 C, and collected and processed by the imaging assembly  201 . For example, the high-power reflected light  219 C can be focused by the imaging optical assembly  203  onto the pixel array  202 , wherein a distant-dependent phase-shift can be determined and correlated with distance to an object or objects  214 C in the scene. The high-power reflected light  219 C, resulting from the high-power illumination  218 C, can be focused on a large fraction of the demodulation pixels in the pixel array, whereas the first and second low-power reflected light  215 A,  215 B resulting from the first low-power illumination  213 A and second low-power illumination  213 B are only focused on a fraction of demodulation pixels in the demodulation pixel array  202 . Consequently, higher resolution data can be obtained when high-power emitted light  216  is employed. 
         [0035]    The optoelectronic module  200  described above may exhibit considerable reduction in power consumption. For example, the low-power emitter region  206  of the hybrid illumination assembly  204  may illuminate an object or objects in a scene until an objected movement is detected, then high-power emitted light can be employed to obtain higher resolution distance data of the object/scene of interest. 
         [0036]    Still further, the optoelectronic module  200  described above may exhibit even greater reduction in power consumption when either the low-power emitter region  206  and/or the high-power emitter region  207  are operated in a pulsed mode. For example, the low-power emitter region  206  (which is an example of a first emitter region) may illuminate an object or objects in a scene for a short period (e.g., a fraction of a second to 1 second) and my cease to illuminate an object or objects in a scene for another short period (e.g., 1 second to a few seconds). This regime may continue until an object in the scene moves. Upon the detection of movement, as outlined above, the high-power mode (as disclosed previously) can be activated; that is the high-power emitter region  207  can be activated. In other cases, the high-power emitter region  207  of the hybrid illumination assembly  204  can be operated in a similar manner. However, the high-power emitter region  207  may illuminate and cease to illuminate the scene at considerably shorter periods (e.g. fractions of a second). The duration of the periods of illumination can be highly dependent on the nature of the objects (e.g., their speed of movement, position change). 
         [0037]    Although in the above examples object movement was detected by a phase shift in the modulated light reflected by an object in a scene, other variations to the optoelectronic module can be used to detect object movement. For example, the low-power emitter region  206  need not illuminate objects in a scene with modulated light. Objects can be illuminated with un-modulated light, wherein the intensity of light reflected from objects in a scene may change and be correlated with movement. Still further other approaches can be used to detect movement such as via triangulation, i.e., where reflected light focused on a pixel array can be used to determine distance to an object (e.g., using the focal length of the imaging optical assembly  203 , and the baseline distance between imaging assembly  201  and low-power illumination assembly  204 ). Hence movement over a given time interval can be determined. 
         [0038]    In previous examples, movement, distance/position change of an object in a scene may initiate a protocol wherein the low-power emitter region  206  ceases to illuminate the scene and the high-power emitter region  207  is activated. Upon activation of the high-power emitter region  207  distance data of the object or objects in a scene can be determined (as disclosed above). 
         [0039]    Still further, the imaging assembly  201  and/or the hybrid illumination assembly  204  may further include other optical filters, passives, other electrical components, and processors and other components (not shown) pertinent to the function of the optoelectronic module  100 . 
         [0040]      FIG. 3A  depicts an example of an optoelectronic module  300  including an autofocus assembly and with low- and high-power emitters operating in a low-power mode. The optoelectronic module  300  can include an imaging assembly  301 , a substrate  301 A (such as a PCB), a low-power illumination assembly  304  (which is an example of a first illumination assembly), a high-power illumination assembly  313  (which is an example of a second illumination assembly), and an autofocus assembly  312 . The imaging assembly  301  can be further composed of an imaging assembly spacer  301 B, a pixel array  302 , such as an array of demodulation pixels, mounted on a substrate  301 A, and an imaging optical assembly  303 . The imaging optical assembly  303  may include a plurality of lens elements, barrels, stops, apertures, and filters. The low-power illumination assembly  304  can be further composed of a low-power emitter  305  (which is an example of a first emitter) such as a light emitting diode, laser, vertical-cavity surface-emitting laser (VCSEL), or VCSEL array, mounted on a substrate  301 A; a first emitter spacer  305 A; and a low-power optical assembly  307  (which is an example of a first optical assembly). In a low-power mode, the low-power emitter  305  emits a low-power emitted light  306  (which is an example of a first emitted light). The low-power emitted light  306  can be any wavelength or range of wavelengths of electromagnetic radiation e.g. visible or non-visible radiation. For example, low-power emitted light  306  can be near-, mid-, or far-infrared radiation. Further the low-power emitted light  306  can be modulated. The low-power emitted light  306  is incident on the low-power optical assembly  307 . The low-power optical assembly  307  can be any one of, or combinations of any one of the following optical elements: a diffraction grating, a microlens array, a lens, a prism, a micro-prism array, a diffractive optical element or a plurality of anyone of the aforementioned or their respective combinations. The low-power optical assembly  307  may further be composed of apertures, spacers, alignment features, and other components pertinent to its function. The low-power emitted light  306  incident on the low-power optical assembly  307  may produce a low-power emission  308  (which is an example of a first emission). 
         [0041]    The low-power emission  308  may produce a first low-power illumination  309 A (which is an example of a first illumination at a first position) incident on an object at a first position  310 A in a scene. The object can be illuminated by the first low-power illumination  309 A when at a particular distance or range of distances (e.g., between a few centimeters and several or even tens of meters). The low-power emission  308  may further produce a second low-power illumination  309 B (which is an example of a first illumination at a second position) on the object at a second position  310 B in the scene. The solid arrow in  FIG. 3A  illustrates movement of the object from the first position  310 A to the second position  310 B in the scene. The low-power emission  308  may encompass a first field-of-view (FOV). The first low-power illumination  309 A and second low-power illumination  309 B may take the form of a pattern of high-contrast features, for example, a discrete array of illuminated dots, lines, or other shapes, or combinations of the aforementioned. The distance between the high-contrast features can be strongly correlated with the intended application of the optoelectronic module  300 ; generally, the distance between the features can be on the order of the dimension of the objects in the scene or smaller. In general, the power required to produce the low-power emission  308 , and subsequent low-power illuminations  309 A and  309 B, is considerably less than the power required to produce a homogenous illumination of the same intensity. 
         [0042]    A first low-power reflected light  311 A (which is an example of a first reflected light at a first position) can be reflected from the object at a first position  310 A and the second low-power reflected light  311 B (which is an example of a first reflected light at a second position) can be reflected from the object at a second position  310 B. The reflected light can be collected and processed by the imaging assembly  301 . For example, the first low-power reflected light  311 A can be imaged by an optical assembly  303  and focused onto a demodulation pixel array  302 , wherein a distant-dependent phase-shift can be determined and correlated with distance from the optoelectronic module  300  to the object at a first position  310 A. Similarly, at another instant in time for example, the second low-power reflected light  311 B can be correlated with distance to the object at a second position  310 B as described above. The detection of a distance or position change between the object at a first position  310 A and the object at a second position  310 B is associated with object movement. Generally, the aforementioned detection of movement of the object from the first position to the second position may activate a high-power mode, e.g., may activate the high-power illumination assembly  313 . However, in other instances, an object entering the scene may also activate a high-power mode. 
         [0043]    The autofocus assembly  312  can be composed of actuating means, e.g., piezoelectric actuators or voice-coil actuators, and/or variable focus lenses, or indeed other known means for adjusting the focus of an imaging optical assembly such as the imaging optical assembly  303 . The autofocus assembly  312  can be engaged to adjust the focus of imaging optical assembly  303  according to the following manner. The low-power emission  308  may produce the first low-power illumination  309 A on the object at a first position  310 A. The first low-power reflected light  311 A can be focused onto the pixel array  302  via the imaging optical assembly  303 . Distance between the optoelectronic module  300  and the object at a first position  310 A can be determined via any of the previous disclosed techniques wherein the autofocus assembly  312  can be appropriately adjusted such that the object at a first position  310 A is in focus with respect to the imaging assembly  301  or indeed another imaging assembly (not shown). 
         [0044]      FIG. 3B  depicts an example of an optoelectronic module having low- and high-power emitters operating in a high-power mode. The high-power illumination assembly  313  is composed of a high-power emitter  314  (which is an example of a second emitter) mounted on a substrate  301 A, a second emitter spacer  314 A, and a high-power optical assembly  316  (which is an example of a second optical assembly). In a high-power mode, the high-power emitter  314  emits a high-power emitted light  315 . The high-power emitted light  315  (which is an example of a second emitted light) can be any wavelength or range of wavelengths of electromagnetic radiation e.g. visible or non-visible radiation. For example, the high-power emitted light  315  can be near-, mid-, or far-infrared radiation. Further the high-power emitted light  315  can be modulated. 
         [0045]    Still further, the high-power emitted light  315  is incident on the high-power optical assembly  316 . The high-power optical assembly  316  can be any one of, or combinations of any one of the following optical elements: a diffraction grating, a microlens array, a lens, a prism, a micro-prism array, a diffractive optical element or a plurality of anyone of the aforementioned or their respective combinations. The high-power optical assembly  316  may further be composed of apertures, spacers, alignment features, and other components pertinent to its function. The high-power emitted light  315  incident on the high-power optical assembly  316  produces a high-power emission  317  (which is an example of a second emission), wherein the high-power emission  317  can be in focus and produce a high-power illumination  318 C (which is an example of a second illumination) on an object or objects  310 C in a scene within a particular range of distances (for example, between a few centimeters and several or even tens of meters). The high-power emission  317  may encompass a second FOV. Further the second FOV may substantially encompass, and can be substantially equivalent to, the first FOV. Both the first and second FOV can be, for example, from about 20° to 140°, and in some cases may be greater depending on the intended application. 
         [0046]    The high-power illumination  318 C can be a homogenous (non-patterned, non-discrete) illumination. In other cases the high-power illumination  318 C may take the form of a dense pattern of high-contrast features, for example, a discrete array of illuminated dots, lines, or other shapes, or combinations of the aforementioned. A high-power reflected light  319 C (which is an example of a second reflected light) can be reflected from an object or objects  310 C, and collected and processed by the imaging assembly  301 . For example, the high-power reflected light  319 C can be focused by the imaging optical assembly  303  onto the pixel array  302 , wherein a distant-dependent phase-shift can be determined and correlated with distance to an object or objects  310 C in the scene. The high-power reflected light  319 C, resulting from the high-power illumination  318 C, can be focused on a large fraction of the demodulation pixels in the pixel array, whereas the first and second low-power reflected light  311 A,  311 B, resulting from the first low-power illumination  309 A and second low-power illumination  309 B, respectively, are only focused on a fraction of demodulation pixels in the demodulation pixel array  302 . Consequently, higher resolution data can be obtained when the high-power illumination assembly  313  is employed. 
         [0047]    The optoelectronic module  300  described above may exhibit considerable reduction in power consumption. For example, the low-power illumination assembly  304  of the optoelectronic module  300  may illuminate an object or objects in a scene until an objected movement is detected, then the high-power illumination assembly  313  can be employed to obtain higher resolution distance data of the object/scene of interest. 
         [0048]    Still further, the optoelectronic module  300  described above may exhibit even greater reduction in power consumption when either the low-power emitter  305  and/or the high-power emitter  313  are operated in a pulsed mode. For example, the low-power emitter  305  may illuminate an object or objects in a scene for a short period (e.g., a fraction of a second to 1 second) and my cease to illuminate an object or objects in a scene for another short period (e.g., 1 second to a few seconds). This regime may continue until an object in the scene moves. Upon the detection of movement, as outlined above, the high-power mode (as disclosed previously) can be activated. In other cases, the high-power emitter  313  can be operated in a similar manner. However, the high-power emitter  313  may illuminate and cease to illuminate the scene at considerably shorter periods (e.g., fractions of a second). The duration of the periods of illumination can be highly dependent on the nature of the objects (e.g., their speed of movement, position change). 
         [0049]    Although in the above examples object movement was detected by a phase shift in the modulated light reflected by an object in a scene, other variations to the optoelectronic module can be used to detect object movement. For example, the low-power illumination assembly  304  need not illuminate objects in a scene with modulated light. Objects can be illuminated with un-modulated light, wherein the intensity of light reflected from objects in a scene may change and be correlated with movement. Still further, other approaches can be used to detect movement such as via triangulation, i.e. where reflected light focused on a pixel array can be used to determine distance to an object (e.g., using the focal length of the imaging optical assembly  303 ; and the baseline distance between imaging assembly  301 , and low-power illumination assembly  304 ; and/or the baseline distance between imaging assembly  301 , and high-power illumination assembly  313 ). Hence movement over a given time interval can be determined. 
         [0050]    In previous examples, movement, distance/position change of an object in a scene may initiate a protocol wherein the low-power emitter  305  ceases to illuminate the scene and the high-power emitter  314  is activated. Upon activation of the high-power emitter  314  distance data of the object or objects in a scene can be determined (as described above). 
         [0051]    Still further, the imaging assembly  301  and/or the low-power illumination assembly  304  and/or the high-power illumination assembly  313  may include other optical filters, passives, other electrical components, and processors and other components (not shown) pertinent to the function of the optoelectronic module  300 . 
         [0052]      FIG. 4A  depicts an example of an optoelectronic module  400  configured to capture stereo images and with low- and high-power emitters operating in a low-power mode. The optoelectronic module  400  includes a substrate  401 Z (such as a PCB), a first imaging assembly  401 A and a second imaging assembly  401 B wherein each first imaging assembly  401 A and second imaging assembly  401 B are composed of a first and second pixel array  402 A,  402 B mounted on a substrate  401 Z, a first and second imaging assembly spacer  401 X,  401 Y, and a first and second imaging optical assembly  403 A,  403 B. The first and second imaging assemblies are separated by a baseline B. In this example, movement of an object can be detected in a low-power mode as described in reference to  FIG. 1A - FIG. 3B  above. Movement of an object can be detected by using the first and/or second imaging optical assemblies  403 A,  403 B. The optoelectronic module  400  can be further composed of a low-power illumination assembly  404  (which is an example of a first illumination assembly) and a high-power illumination assembly  412  (which is an example of a second illumination assembly). The imaging assemblies  401 A,  401 B can be further composed of pixel arrays  402 A,  402 B such as an array of demodulation pixels, and an imaging optical assemblies  403 A,  403 B. The imaging optical assemblies  403 A,  403 B may include a plurality of lens elements, barrels, stops, apertures, and filters. The low-power illumination assembly  404  can be further composed of a low-power emitter  405  (which is an example of a first emitter) such as a light emitting diode, laser, vertical-cavity surface-emitting laser (VCSEL), or VCSEL array; a first emitter spacer  405 A, mounted on a substrate  401 Z; and a low-power optical assembly  407  (which is an example of a first optical assembly). In a low-power mode, the low-power emitter  405  emits a low-power emitted light  406  (which is an example of a first emitted light). The low-power emitted light  406  can be any wavelength or range of wavelengths of electromagnetic radiation (e.g. visible or non-visible radiation). For example, low-power emitted light  406  can be near-, mid-, or far-infrared radiation. Further the low-power emitted light  406  can be modulated. The low-power emitted light  406  is incident on the low-power optical assembly  407 . The low-power optical assembly  407  can be any one of, or combinations of, the following optical elements: a diffraction grating, a microlens array, a lens, a prism, a micro-prism array, a diffractive optical element or a plurality of any one of the aforementioned or their respective combinations. The low-power optical assembly  407  may further be composed of apertures, spacers, alignment features, and other components pertinent to its function. The low-power emitted light  406  incident on the low-power optical assembly  407  may produce a low-power emission  408  (which is an example of a first emission). 
         [0053]    The low-power emission  408  may produce a first low-power illumination  409 A (which is an example of a first illumination at a first position) incident on an object at a first position  410 A in a scene. The object can be illuminated by the first low-power illumination  409 A when at a particular distance or range of distances (e.g., between a few centimeters and several or even tens of meters). The low-power emission  408  may further produce a second low-power illumination  409 B (which is an example of a first illumination at a second position) on the object at a second position  410 B in the scene. The solid arrow in  FIG. 4A  illustrates movement of the object from the first position  410 A to the second position  410 B in the scene. The low-power emission  408  may encompass a first field-of-view (FOV). The first low-power illumination  409 A and second low-power illumination  409 B may take the form of a pattern of high-contrast features, for example, a discrete array of illuminated dots, lines, or other shapes, or combinations of the aforementioned. The distance between the high-contrast features can be strongly correlated with the intended application of the optoelectronic module  400 ; generally, the distance between the features can be on the order of the dimension of the objects in the scene or smaller. In general, the power required to produce the low-power emission  408 , and subsequent low-power illuminations  409 A and  409 B, is considerably less than the power required to produce a homogenous illumination of the same intensity. 
         [0054]    A first low-power reflected light  411 A (which is an example of a first reflected light at a first position) can be reflected from the object at a first position  410 A and the second low-power reflected light  411 B (which is an example of a first reflected light at a second position) can be reflected from the object at a second position  410 B. The reflected light can be collected and processed by both the imaging assemblies  401 A,  401 B. For example, the first low-power reflected light  411 A can be imaged by the optical assemblies  403 A,  403 B and focused onto a demodulation pixel arrays  402 A,  402 B, wherein a disparity can be determined (e.g., via standard stereo matching algorithms) and correlated with distance from the optoelectronic module  400  to the object at a first position  410 A. Similarly, at another instant in time for example, the second low-power reflected light  411 B can be correlated with distance to the object at a second position  410 B as described above. The detection of a distance or position change between the object at a first position  410 A and the object at a second position  410 B is associated with object movement. Generally, the aforementioned detection of movement of the object from the first position to the second position may activate a high-power mode, e.g. may activate the high-power illumination assembly  412 . However, in other instances, an object entering the scene may also activate a high-power mode. 
         [0055]      FIG. 4B  depicts an example of an optoelectronic module with low- and high-power emitters operating in a high-power mode. The high-power illumination assembly  412  is composed of a high-power emitter  413  (which is an example of a second emitter) mounted on a substrate  401 Z, a second emitter spacer  413 A, and a high-power optical assembly  415  (which is an example of a second optical assembly). In a high-power mode, the high-power emitter  413  emits a high-power emitted light  414  (which is an example of a second emitted light). The high-power emitted light  414  can be any wavelength or range of wavelengths of electromagnetic radiation e.g. visible or non-visible radiation. For example, the high-power emitted light  414  can be near-, mid-, or far-infrared radiation. Further the high-power emitted light  414  can be modulated. 
         [0056]    Still further, the high-power emitted light  414  is incident on the high-power optical assembly  415 . The high-power optical assembly  415  can be any one of, or combinations of, the following optical elements: a diffraction grating, a microlens array, a lens, a prism, a micro-prism array, a diffractive optical element or a plurality of anyone of the aforementioned or their respective combinations. The high-power optical assembly  415  may further be composed of apertures, spacers, alignment features, and other components pertinent to its function. The high-power emitted light  414  incident on the high-power optical assembly  415  produces a high-power emission  416  (which is an example of a second emission), wherein the high-power emission  416  can be in focus and produce a high-power illumination  417 C (which is an example of a second illumination) on an object or objects  410 C in a scene within a particular range of distances (for example, between a few centimeters and several or even tens of meters). The high-power emission  416  may encompass a second FOV. Further the second FOV may substantially encompass, and can be substantially equivalent, to the first FOV. Both the first and second FOV can be, for example, from about 20° to 140°, and in some instances may be greater depending on the intended application. 
         [0057]    The high-power illumination  417 C can be a homogenous (non-patterned, non-discrete) illumination. In other cases the high-power illumination  417 C may take the form of a dense pattern of high-contrast features, for example, a discrete array of illuminated dots, lines, or other shapes, or combinations of the aforementioned. A high-power reflected light  418 C (which is an example of a second reflected light) can be reflected from an object or objects  410 C, and collected and processed by the imaging assemblies  401 A,  401 B. For example, the high-power reflected light  418 C can be focused by the imaging optical assemblies  403 A,  403 B onto the pixel arrays  402 A,  402 B wherein a disparity can be determined (e.g., via standard stereo matching algorithms) and correlated with distance from the optoelectronic module  400  to the object. The high-power reflected light  418 C, resulting from the high-power illumination  417 C, can be focused on a large fraction of the demodulation pixels in the pixel arrays  402 A,  402 B, whereas the first and second low-power reflected light  411 A,  411 B, resulting from the first low-power illumination  409 A and second low-power illumination  409 B, respectively, are only focused on a fraction of demodulation pixels in the demodulation pixel arrays  402 A,  402 B. Consequently, higher resolution data can be obtained when the high-power illumination assembly  412  is employed. 
         [0058]    In previous examples, movement, distance/position change of an object in a scene may initiate a protocol wherein the low-power emitter  405  ceases to illuminate the scene and the high-power emitter  413  is activated. Upon activation of the high-power emitter  413  distance data of the object or objects in a scene can be determined (as described above). 
         [0059]    Still further, the imaging assembly  401  and/or the low-power illumination assembly  404  and/or the high-power illumination assembly  412  may further include other optical filters, passives, other electrical components, and processors and other components (not shown) pertinent to the function of the optoelectronic module  400 . 
         [0060]    Further, in any of the examples described above, the low-power mode can be sufficient for near-range image capture (where the distance between the pattern features can be very small—so sufficient illumination is supplied to near object using the low-power mode). In such an example, the high-power mode is used for far objects. 
         [0061]    The various implementation of the optoelectronic modules described in the above examples may further include, processors, other electrical components or circuit elements (e.g., transistors, resistors, capacitive and inductive elements) pertinent to the function of the optoelectronic modules and apparent to a person of ordinary skill in the art. Moreover, although the present invention has been described in detail with respect to various implementations described above, other implementations including combinations or subtractions of various described features above, are also possible. Thus, other implementations are within the scope of the claims.