Optical imaging modules and optical detection modules including a time-of-flight sensor
The present disclosure describes optical imaging and optical detection modules that include sensors such as time-of-flight (TOF) sensors. Various implementations are described that, in some instances, can help reduce the amount of optical cross-talk between active detection pixels and reference pixels and/or can facilitate the ability of the sensor to determine an accurate phase difference to be used, for example, in distance calculations.
1. An optoelectronic module comprising:
an illumination source;
a sensor including spatially distributed detection pixels and at least one reference pixel;
an optics member disposed over the illumination source and the sensor, the optics member having a first transmissive region over the illumination source and a second transmissive region over the detection pixels;
a light barrier separating an emission chamber of the module from a detection chamber of the module, wherein the illumination source and the at least one reference pixel are in the emission chamber, and wherein the detection pixels are in the detection chamber; and
a partially reflective coating on a surface of the first transmissive region over the illumination source wherein the coating is partially reflective with respect to a wavelength detectable by the reference pixel and is arranged such that some light from the illumination source is reflected by the coating toward the at least one reference pixel.
2. The optoelectronic module of claim 1 including a partially reflective coating on a surface of the first transmissive region facing the illumination source.
3. The optoelectronic module of claim 1 including a partially reflective coating on a surface of the first transmissive region facing away from the illumination source.
4. The optoelectronic module of claim 1 including a partially reflective coating on each of opposite surfaces of the first transmissive region.
5. The optoelectronic module of claim 1 including a reflective coating on a surface of the light barrier facing the illumination source.
6. The optoelectronic module of claim 1 wherein the optics member includes a non-transmissive region separating the first and second transmissive regions, the non-transmissive region having a reflective coating on a surface facing the illumination source and arranged such that some light from the illumination source is reflected by the reflective coating toward the at least one reference pixel.
7. An optoelectronic module comprising:
an illumination source;
a sensor including spatially distributed detection pixels and at least one reference pixel;
an optics member disposed over the illumination source and the sensor, the optics member having a first transmissive region over the illumination source and a second transmissive region over the detection pixels, wherein the first transmissive region has a first coating on a first surface facing the illumination source and a second coating on a second surface facing away from the illumination source;
a light barrier separating an emission chamber of the module from a detection chamber of the module, wherein the illumination source and the at least one reference pixel are in the emission chamber, and wherein the detection pixels are in the detection chamber; and
wherein each of the coatings is at least one of an optical filter coating, a partially-reflective coating, an anti-reflective coating or a non-transmissive coating.
8. The optoelectronic module of claim 7 wherein at least one the first or second coating comprises black chrome.
9. The optoelectronic module of claim 7 including a respective black chrome coating on each of opposite surfaces of the first transmissive region.
10. The optoelectronic module of claim 7 wherein each of the one of more surfaces of the first transmissive region has a black chrome coating and an optical filter coating thereon.
11. The optoelectronic module of claim 7 further including a passive optical element mounted on, or incorporated into, the first transmissive window.
12. The optoelectronic module of claim 11 wherein the passive optical element includes at least one of a reflective patch, a diffractive optical element, or a refractive optical element.