Method and apparatus for increasing the frame rate of a time of flight measurement

Patent metadata

Field	Value
Publication number	US-2016290790-A1
Application number	US-201514675233-A
Country	US
Kind code	A1
Filing date	Mar 31, 2015
Priority date	Mar 31, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

An apparatus is described that includes a pixel array having time-of-flight pixels. The apparatus also includes clocking circuitry coupled to the time-of-flight pixels. The clocking circuitry comprises a multiplexer between a multi-phase clock generator and the pixel array to multiplex different phased clock signals to a same time-of-flight pixel. The apparatus also includes an image signal processor to perform distance calculations from streams of signals generated by the pixels at a first rate that is greater than a second rate at which any particular one of the pixels is able to generate signals sufficient to perform a single distance calculation.

First claim

1 . An apparatus, comprising:
a pixel array having time-of-flight pixels; clocking circuitry coupled to said time-of-flight pixels, said clocking circuitry comprising a multiplexer between a multi-phase clock generator and said pixel array to multiplex different phased clock signals to a same time-of-flight pixel; an image signal processor to perform distance calculations from streams of signals generated by said pixels at a first rate that is greater than a second rate at which any particular one of the pixels is able to generate signals sufficient to perform a single distance calculation.

2 . The apparatus of claim 1 wherein said multi-phase clock generator is to generate I+, Q+, I− and Q− clock signals.

3 . The apparatus of claim 2 wherein said multiplexer is coupled to said multi-phase clock generator to receive each of said I+, Q+, I− and Q− clock signals.

4 . The apparatus of claim 1 further comprising output channels from different pixels to support a distance measurement being calculated for one of the pixels on a next clock cycle after a distance measurement has been calculated for another of the pixels.

5 . The apparatus of claim 1 wherein said multiplexer has an output coupled to more than one of said pixels.

6 . The apparatus of claim 1 wherein said multiplexer has an output coupled to only one multiplexer.

7 . The apparatus of claim 1 wherein said multiplexer is coupled to receive all differently phased time of flight clock signals.

8 . The apparatus of claim 1 wherein said multiplexer is coupled to receive two differently phased clock signals.

9 . A method, comprising:
generating multiple, differently phased clock signals for a time-of-flight distance measurement; routing each of said differently phased clock signals to different time-of-flight pixels; performing time-of-flight measurements from charge signals from said pixels at a rate that is greater than a rate at which any of the time-of-flight pixels generate charge signals sufficient for a time-of-flight distance measurement.

10 . The method of claim 9 wherein said pixels each receive a different clock.

11 . The method of claim 10 wherein said pixels receive more than one of said different clocks.

12 . The method of claim 11 wherein different ones of said clocks are multiplexed into a same pixel.

13 . The method of claim 11 wherein said pixels each receive all of the clocks used for a time-of-flight distance measurement.

14 . The method of claim 11 wherein said pixels receive two of the clocks used for a time-of-flight measurement.

15 . A computing system, comprising:
a plurality of processors; a memory controller coupled to said plurality of processors; a camera, said camera having
a pixel array having time-of-flight pixels;
clocking circuitry coupled to said time-of-flight pixels, said clocking circuitry comprising a multiplexer between a multi-phase clock generator and said pixel array to multiplex different phased clock signals to a same time-of-flight pixel;
an image signal processor to perform distance calculations from streams of signals generated by said pixels at a first rate that is greater than a second rate at which any particular one of the pixels is able to generate signals sufficient to perform a single distance calculation.

16 . The apparatus of claim 15 wherein said multi-phase clock generator is to generate I+, Q+, I− and Q− clock signals.

17 . The apparatus of claim 16 wherein said multiplexer is coupled to said multi-phase clock generator to receive each of said I+, Q+, I− and Q− clock signals.

18 . The apparatus of claim 15 further comprising output channels from different pixels to support a distance measurement being calculated for one of the pixels on a next clock cycle after a distance measurement has been calculated for another of the pixels.

19 . The apparatus of claim 15 wherein said multiplexer has an output coupled to more than one of said pixels.

20 . The apparatus of claim 15 wherein said multiplexer has an output coupled to only one multiplexer.

Assignees

• Google Inc

Inventors

• Wu Honglei

Classifications

• G01S17/86

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• G01S17/894

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• H04N13/161

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• G06T7/50

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