Method for detecting objects with visible light
A method for detecting an object using visible light comprises providing a visible-light source having a function of illuminating an environment. The visible-light source is driven to emit visible light in a predetermined mode, with visible light in the predetermined mode being emitted such that the light source maintains said function of illuminating an environment. A reflection/backscatter of the emitted visible light is received from an object. The reflection/backscatter is filtered over a selected wavelength range as a function of a desired range of detection from the light source to obtain a light input. The presence or position of the object is identified with the desired range of detection as a function of the light input and of the predetermined mode.
1. A method for detecting an object using visible light, comprising:
providing a white solid-state visible-light source having a function of illuminating an environment;
driving the visible-light source to emit visible light in a predetermined pulse mode, with visible light in the predetermined pulse mode being emitted such that the light source maintains said function of illuminating an environment;
receiving a reflection/backscatter of the emitted visible light from an object;
filtering the reflection/backscatter over a selected wavelength range of 400 nm to 750 nm as a function of a desired range of detection from the light source to obtain a light input having a shorter pulse on a time scale than a Pulse of the visible light;
detecting the light input with the shorter pulse; and
identifying at least one of a presence and a position of the object with the desired range of detection solely as a function of the detected light input with the shorter pulse and of the predetermined pulse mode.
2. The method according to claim 1 , wherein providing the light source comprises providing at least one phosphor-converted light-emitting diode.
3. The method according to claim 2 , wherein filtering the reflection/backscatter comprises obtaining the light input in blue emission ranging between 400 nm to 500 nm from the phosphor-converted light-emitting diode for detection at short range.
4. The method according to claim 2 , wherein filtering the reflection/backscatter comprises obtaining the light input in broadband luminescent emission from the phosphor-converted light-emitting diode for detection at long range.
5. The method according to claim 1 , wherein filtering the reflection/backscatter comprises filtering with an optical interference filter.
6. The method according to claim 1 , wherein driving the visible-light source in the predetermined mode comprises driving the visible-light source in a pulse-width modulation.
7. The method according to claim 1 , wherein filtering the reflection/backscatter over a selected wavelength range to obtain a light input comprises obtaining the light input in a visible wavelength.
8. The method according to claim 1 , wherein driving the visible-light source comprises driving the visible-light source to emit light in pulse-width modulation, identifying at least one of a presence and a position of the object comprises identifying rapid transients in the reflection/backscatter, and further comprising calculating a distance of the object from the rapid transients received and rapid transients from the pulse-width modulation.