3D Vision On A Chip
First Claim
1. A 3D camera for determining distances to regions in a scene comprising:
- a photosurface having a plurality of pixels each of which comprises a circuit having a light sensitive element that provides a current responsive to light incident thereon, wherein the circuit comprises,at least one amplifier inside each pixel, having an input and an output;
at least one feedback capacitor separate from the light sensitive element and connected to the at least one amplifier by a plurality of connection switches such that for a first combination of open and closed connection switches a first terminal of the capacitor is connected to the input of the amplifier and a second terminal of the capacitor is connected to the output of the amplifier, and for a second combination of open and closed connection switches the first terminal of the capacitor is connected to the output of the amplifier and the second terminal of the capacitor is connected to the input of the amplifier;
at least one controllable connection inside each pixel through which the current flows from the light sensitive element into the input of the at least one amplifier;
a light source; and
a controller that,controls the light source to illuminate the scene with gated light,gates or modulates the current from the light sensitive element of each pixel in the photosurface through the at least one controllable connection by opening or closing the at least one controllable connection of each pixel in the photosurface to gate the pixel on and off responsive to the time dependence of the gating or modulation of the light,controls the at least one controllable connection to correct for biases caused by at least one of background light or dark current, anddetermines a distance to a region imaged on a pixel responsive to an amount of charge integrated on the at least one feedback capacitor responsive to the gated or modulated current and the corrected biases;
the at least one controllable connection including at least one gate switch that connects the light sensitive element to one amplifier and the controller opens and closes the at least one gate switch to gate the pixel on and off and determines a distance to a region imaged on the pixel responsive to an amount of charge integrated on the feedback capacitor of the at least one amplifier during times at which the pixel is gated on.
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Accused Products
Abstract
A 3D camera for determining distances to regions in a scene wherein gating or modulating apparatus for the 3D camera is incorporated on a photosurface of the camera on which light detectors of the camera are also situated. Each pixel in the photosurface may include its own pixel circuit for gating the pixel on or off or for modulating the sensitivity of the pixel to incident light. The circuit may comprise at least one amplifier inside the pixel, at least one feedback capacitor separate from the light sensitive element and connected between the input and output of each of the at least one amplifier, and at least one controllable connection through which current flows from the light sensitive element into the input of the at least one amplifier. The 3D camera may further include a light source and a controller.
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Citations
20 Claims
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1. A 3D camera for determining distances to regions in a scene comprising:
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a photosurface having a plurality of pixels each of which comprises a circuit having a light sensitive element that provides a current responsive to light incident thereon, wherein the circuit comprises, at least one amplifier inside each pixel, having an input and an output; at least one feedback capacitor separate from the light sensitive element and connected to the at least one amplifier by a plurality of connection switches such that for a first combination of open and closed connection switches a first terminal of the capacitor is connected to the input of the amplifier and a second terminal of the capacitor is connected to the output of the amplifier, and for a second combination of open and closed connection switches the first terminal of the capacitor is connected to the output of the amplifier and the second terminal of the capacitor is connected to the input of the amplifier; at least one controllable connection inside each pixel through which the current flows from the light sensitive element into the input of the at least one amplifier; a light source; and a controller that, controls the light source to illuminate the scene with gated light, gates or modulates the current from the light sensitive element of each pixel in the photosurface through the at least one controllable connection by opening or closing the at least one controllable connection of each pixel in the photosurface to gate the pixel on and off responsive to the time dependence of the gating or modulation of the light, controls the at least one controllable connection to correct for biases caused by at least one of background light or dark current, and determines a distance to a region imaged on a pixel responsive to an amount of charge integrated on the at least one feedback capacitor responsive to the gated or modulated current and the corrected biases; the at least one controllable connection including at least one gate switch that connects the light sensitive element to one amplifier and the controller opens and closes the at least one gate switch to gate the pixel on and off and determines a distance to a region imaged on the pixel responsive to an amount of charge integrated on the feedback capacitor of the at least one amplifier during times at which the pixel is gated on. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A 3D camera for determining distances to regions in a scene comprising:
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a photosurface having a plurality of pixels each of which comprises a circuit having a light sensitive element that provides a current responsive to light incident thereon, wherein the circuit for each pixel comprises, at least one amplifier inside each pixel, having an input and an output, the at least one amplifier being an operational amplifier; at least one feedback capacitor separate from the light sensitive element and connected between the input and output of each of the at least one amplifier; at least one controllable connection inside each pixel through which the current flows from the light sensitive element into the input of the at least one amplifier; a light source; and a controller that, controls the light source to illuminate the scene with gated light, gates or modulates the current from the light sensitive element of each pixel in the photosurface through the at least one controllable connection responsive to the time dependence of the gating or modulation of the light, controls the at least one controllable connection to correct for biases caused by at least one of background light or dark current, and determines a distance to a region imaged on a pixel responsive to an amount of charge integrated on the at least one feedback capacitor responsive to the gated or modulated current and the corrected biases; the at least one controllable connection including at least one gate switch and the controller opens and closes the at least one gate switch to gate the pixel on and off and determines the distance to the region imaged on the pixel responsive to an amount of charge integrated on the at least one feedback capacitor of the at least one amplifier during times at which the pixel is gated on; the at least one amplifier including first and second amplifiers having first and second feedback capacitors respectively and the at least one gate switch comprises first and second gate switches, the first gate switch connecting the light sensitive element to the input of the first amplifier and the second gate switch connecting the light sensitive element to the input of the second amplifier. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method of generating a signal responsive to light reflected by an object from a light pulse radiated by a light source, wherein the signal is corrected for effects of background light and dark current, the method comprising:
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sensing the reflected light with a gated sensor that is gated on for a first gate period at a first time determined responsive to a time at which the light pulse is radiated so that at least some of the reflected light from the light pulse is incident on the sensor to generate a first signal having a first value; gating the sensor on for a second gate period at a second time determined responsive to the time at which the light pulse is radiated so that during the second gate period light from the light source is not incident on the sensor to generate a second signal having a second value; and subtracting the second value from the first value to form a corrected value. - View Dependent Claims (19, 20)
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Specification