SPECTRAL IMAGER

摘要

A system and method are provided for spectral imaging an object or scene 2. A first image 2a of the object or scene 2 is projected on a spatial modulator 6 and divided into a plurality of first image segments 2a′ modulated with a respective plurality of modulation frequencies f1-fN. A spectrally resolved second image segment 2b′ of each first image segment 2a′ is projected onto a sensor 4 forming a second image 2b in such a way that overlapping spectral components λ of different second image segments 2b′ on the sensor 4 originating from different first image segments 2a′ have distinct modulation frequencies f1-fN. The projected second image segments 2b′ are read out from the sensor 4 and demodulated according to the distinct modulation frequencies f1-fN. In this way projected second image segments 2b′ overlapping on the sensor 4 may be distinguished on the basis of the distinct modulation frequencies f1-fN.

主权项

1. Spectral imager for imaging a multispectral object, the spectral imager comprising
a projection system defining an object plane and a first image plane, wherein the projection system is arranged for spatially imaging the object plane in the first image plane as a first image; a sensor arranged for detecting radiation from the multispectral object; a spectral resolving element arranged in a light path between the first image plane and the sensor; a spatial modulator comprising
a plurality of modulator segments arranged in the first image plane for spatially dividing the first image into a plurality of first image segments, wherein each modulator segment is arranged for providing a time-dependent modulation of a respective first image segment; anddriving circuitry arranged for driving the plurality of modulator segments with a respective plurality of time-dependent modulation functions thereby passing the plurality of first image segments with a respective time-dependent modulation onto the sensor; and a readout device arranged for reading out the sensor and comprising a demodulator arranged for demodulating the time-dependent modulation functions for the purpose of distinguishing between the passed first image segments overlapping on the sensor on the basis of said time-dependent modulation functions; wherein the projection system further defines a second image plane, wherein the projection system is arranged for spatially imaging each spectral component of the first image as a second image in the second image plane, displaced within the second image plane by the spectral resolving element as a function of a wavelength of said spectral component, wherein each second image comprises a plurality of second image segments, wherein each second image segment is a spatial image of a respective first image segment and is modulated on the sensor according to a time-dependent modulation function of the said respective first image segment; and the sensor comprises a plurality of sensing elements arranged in the second image plane for spatially resolving the second images.