Apparatuses, systems, and methods for selectively suppressing ambient light in an image sensor
An imaging device may include (1) an aperture, (2) a lens positioned to direct light received through the aperture to a front side of an image sensor; and (3) the image sensor. The image sensor may include (1) a light capture layer including a photosensitive material that is dimensioned such that (a) a first portion of the light having less than a predetermined wavelength is captured by the light capture layer, producing a current, and (b) a second portion of the light having at least the predetermined wavelength passes through the light capture layer, (2) a conduction pathway that conducts the produced current to a current sink, and (3) an image sensor layer that includes at least one image sensor element positioned to receive the second portion of the light that passes through the light capture layer. Various other devices, systems, and methods are also disclosed.
1. An imaging device comprising:
an aperture;
a lens positioned to direct light received through the aperture to a front side of an image sensor; and
the image sensor comprising:
a light capture layer comprising a photosensitive material that is dimensioned such that:
a first portion of the light having less than a predetermined wavelength is captured by the light capture layer, producing a current in the light capture layer; and
a second portion of the light having at least the predetermined wavelength passes through the light capture layer;
a conduction pathway, electrically coupled to the light capture layer, that conducts the current produced in the light capture layer to a current sink; and
an image sensor layer coupled to the light capture layer, the image sensor layer comprising at least one image sensor element positioned to receive the second portion of the light that passes through the light capture layer.
2. The imaging device of claim 1 , wherein the current sink comprises at least one of:
a grounding terminal;
an open current drain;
an open current collector; or
a capacitor.
3. The imaging device of claim 1 , further comprising image sensor circuitry electrically coupled to the at least one image sensor element, wherein the current sink is not electrically coupled to the image sensor circuitry.
4. The imaging device of claim 1 , wherein:
the light capture layer comprises an n-type semiconductor;
the image sensor layer comprises a p-type semiconductor; and
the image sensor element comprises an additional n-type semiconductor disposed at least partially within the p-type semiconductor.
5. The imaging device of claim 1 , wherein:
the image sensor further comprises an incident layer coupled to the light capture layer and positioned between the lens and the light capture layer; and
the incident layer passes the light from the lens to the light capture layer.
6. The imaging device of claim 5 , wherein the incident layer comprises an additional p-type semiconductor.
7. The imaging device of claim 1 , wherein:
the image sensor layer comprises a plurality of image sensor elements, the at least one image sensor element included in the plurality of image sensor elements; and
the light capture layer overlaps the plurality of image sensor elements.
8. The imaging device of claim 1 , wherein the at least one image sensor element has a greater thickness in a direction of light flow through the image sensor than the light capture layer.
9. The imaging device of claim 1 , further comprising a printed circuit board positioned behind the image sensor and electrically coupled to the at least one image sensor element.
10. The imaging device of claim 1 , wherein the imaging device comprises part of a local area imaging assembly configured to track at least one object in an area surrounding the local area imaging assembly.
11. The imaging device of claim 1 , wherein the imaging device comprises part of a local area imaging assembly configured to determine a depth between the local area imaging assembly and one or more objects in an area surrounding the local area imaging assembly.
12. The imaging device of claim 1 , wherein the imaging device comprises part of at least one of:
a virtual reality headset; or
an augmented reality headset.
13. A system comprising:
a head-mounted display; and
an imaging device that comprises:
an aperture;
a lens positioned to direct light received through the aperture to a front side of an image sensor;
the image sensor comprising:
a light capture layer comprising a photosensitive material that is dimensioned such that:
a first portion of the light having less than a predetermined wavelength is captured by the light capture layer, producing a current in the light capture layer; and
a second portion of the light having at least the predetermined wavelength passes through the light capture layer;
a conduction pathway, electrically coupled to the light capture layer, that conducts the current produced in the light capture layer to a current sink; and
an image sensor layer coupled to the light capture layer, the image sensor layer comprising at least one image sensor element positioned to receive the second portion of the light that passes through the light capture layer.
14. The system of claim 13 , wherein the current sink comprises at least one of:
a grounding terminal;
an open current drain;
an open current collector; or
a capacitor.
15. The system of claim 13 , wherein:
the light capture layer comprises an n-type semiconductor;
the image sensor layer comprises a p-type semiconductor; and
the image sensor element comprises an additional n-type semiconductor disposed at least partially within the p-type semiconductor.
16. The system of claim 13 , further comprising a printed circuit board positioned behind the image sensor and electrically coupled to the at least one image sensor element.
17. The system of claim 13 , further comprising a local area imaging assembly that comprises the imaging device and an illumination source that emits light onto one or more objects in a local area such that the emitted light is reflected back to the local area imaging assembly after reaching the one or more objects, wherein:
the light received through the aperture comprises the light reflected back from the one or more objects; and
the local area imaging assembly is configured to determine a depth between the local area imaging assembly and the one or more objects based on the light reflected back from the one or more objects.
18. The system of claim 13 , further comprising a hand-held controller that comprises at least one light-emitting element, wherein:
the light received through the aperture comprises light emitted by the at least one light-emitting element of the hand-held controller; and
the imaging device comprises part of a local area imaging assembly configured to track the hand-held controller based on the light emitted by the at least one light-emitting element of the hand-held controller.
19. The system of claim 13 , wherein the head-mounted display comprises at least one of:
a virtual reality headset; or
an augmented reality headset.
20. A method comprising:
forming a light capture layer on a front side of an image sensor layer comprising at least one image sensor element, the light capture layer comprising a photosensitive material that is dimensioned such that:
a first portion of light received through an aperture having less than a predetermined wavelength is captured by the light capture layer, producing a current in the light capture layer; and
a second portion of the light having at least the predetermined wavelength passes through the light capture layer to the at least one image sensor element;
electrically coupling a conduction pathway to the light capture layer that conducts the current produced in the light capture layer to a current sink; and
positioning the image sensor layer and the light capture layer within an imaging device behind a lens positioned to direct light received through the aperture of the imaging device to the light capture layer.