Sectional multi spectral sensor with optical blurring
In a first aspect of the disclosure there is provided a multi-spectral optical sensor comprising: a monolithic semiconductor chip defining a plurality of subarrays of optical detector regions, each array comprising the same number and relative spatial arrangement of optical detector regions; a plurality of optical filters; and a plurality of lens elements, wherein each optical filter is positioned between a corresponding lens element and a corresponding subarray of optical detector regions such that light from a scene incident on any one of the lens elements along a direction of incidence propagates through the corresponding optical filter towards a corresponding one of the optical detector regions of the corresponding subarray of optical detector regions, which corresponding one of the optical detector regions depending on the direction of incidence, and wherein the incident light forms an out-of-focus image of the scene at a plane of the optical detector regions.
1 . A multi-spectral optical sensor, comprising:
a monolithic semiconductor chip defining a plurality of subarrays of optical detector regions, each array comprising a same number and relative spatial arrangement of optical detector regions;
a plurality of optical filters;
a plurality of lens elements; and
a spacer disposed on the monolithic semiconductor chip, wherein the spacer defines a plurality of apertures, wherein each aperture is aligned with a corresponding lens element, a corresponding optical filter, and a corresponding subarray of optical detector regions,
wherein the corresponding optical filter is positioned between the corresponding lens element and the corresponding subarray of optical detector regions such that incident light from a scene incident on any one of the lens elements along a direction of incidence propagates through the corresponding optical filter towards a corresponding one of the optical detector regions of the corresponding subarray of optical detector regions, wherein which of the corresponding one of the optical detector regions depends on the direction of incidence, and
wherein the incident light forms an out-of-focus image of the scene at a plane of the optical detector regions, and
wherein a blur circle of each lens element of a first of the optical detector regions forming the out-of-focus image overlaps a second of the optical detector regions.
2 . The multi-spectral optical sensor of claim 1 , wherein each lens element is aligned to focus the incident light onto a focal plane adjacent the plane of the optical detector regions to form the out-of-focus image at the plane of the optical detector regions.
3 . The multi-spectral optical sensor of claim 2 , wherein the focal plane of each lens element is arranged at a predetermined distance from the plane of the optical detector regions.
4 . The multi-spectral optical sensor of claim 1 , comprising:
a plurality of diffuser elements configured to diffuse the incident light to form the out-of-focus image at the plane of the optical detector regions.
5 . The multi-spectral optical sensor of claim 1 , wherein the plurality of lens elements comprises a micro lens array (MLA) or a micro Fresnel lens array.
6 . The multi-spectral optical sensor of claim 5 , wherein the plurality of lens elements are defined by, or formed on, an optical substrate.
7 . A multi-spectral optical system, comprising:
the multi-spectral optical sensor of claim 1 ; and
a processing resource,
wherein the multi-spectral optical sensor and the processing resource are configured for communication with one another,
wherein the processing resource is configured to:
associate different electrical signals generated by different optical detector regions of a same subarray with light incident on and forming an out-of-focus image on the multi-spectral optical sensor from a scene along corresponding different directions of incidence, and
associate different electrical signals generated by corresponding optical detector regions of different subarrays with light incident on and forming an out-of-focus image on the multi-spectral optical sensor from the scene along a same direction of incidence.
8 . The multi-spectral optical system of claim 7 , wherein the processing resource is configured to associate the electrical signal generated by an optical detector region with an optical transmission spectrum of the corresponding optical filter.
9 . The multi-spectral optical system of claim 7 , wherein the processing resource is configured to determine an ambient light source classification for each direction of incidence of a plurality of different directions of incidence based on a comparison between electrical signal values corresponding to each direction of incidence and predefined spectral data.
10 . The multi-spectral optical system of claim 9 , wherein the predefined spectral data comprises a plurality of discrete spectra, each spectrum corresponding to a different known type or kind of ambient light source.
11 . The multi-spectral optical system of claim 7 , wherein the processing resource is configured to adjust electrical signal values generated by the different optical detector regions of the same subarray of optical detector regions to compensate for any differences in optical transmission spectra of the corresponding optical filter arising as a result of propagation of convergent light through the corresponding optical filter along different directions of propagation for the different optical detector regions of the same subarray of optical detector regions.
12 . An image sensing system, comprising:
the multi-spectral optical system of claim 7 ; and
an image sensor having a known spatial relationship relative to the multi-spectral optical sensor,
wherein the image sensor and the processing resource are configured for communication with one another, and
wherein the processing resource is configured to adapt an image sensed by the image sensor based upon an ambient light source classification for each direction of incidence.
13 . The image sensing system of claim 12 , wherein the processing resource is configured to adapt the image by white-balancing the image based upon one or more parameters of the ambient light source classification for each direction.
14 . The image sensing system of claim 13 , wherein to adapt the image further comprises gradient white-balancing the image based upon one or more parameters of the ambient light source classification for each direction of incidence.
15 . An electronic device comprising the multi-spectral optical sensor of claim 1 .
16 . An electronic device comprising the multi-spectral optical system of claim 7 .
17 . An electronic device comprising the image sensing system of claim 12 .