> The company is Canesta.
>  http://canesta.com/

> They use time of flight of light to measure distances on a pixel by
> pixel basis.
> They drive an LED with a square wave waveform at 44 MHz. =A0Then they
> measure the inphase and out of phase light incident on two pixel
> arrays that are driven by the same waveform with phase offsets.
>
> Description of process
> http://www.canesta.com/assets/pdf/technicalpapers/Canesta101.pdf
>
> It looks pretty cool since the computations required are much reduced.

Extremely impressive, if it works.
And it appears that it does, although they may yet not survive the
aborning process.

Having a Hitachi R&D head enthuse about the system in general and use
their products in a demo doesn't hurt.
Having Honda as an investor also helps.

_________

Brain 1st think says it's implicit rather than explicit time of flight
that they are measuring.
ie they compare in phase and out of phase reflected light receptors to
determine how long it took a light pulse to return. For the basic
system that allows an essentially computationless result apart from
offsets due to eg background light and scaling factors across a target
of varying reflectivity. They claim mm precision at 2 feet and cm at 8
feet (their mixed units).

This system should be able to be employed with ease in a single sensor
system for ranging (and almost certainly already is). Their 44 MHz
square wave LED drive is easily enough achieved. They sum over 12 ms
which is one factor in setting the maximum possible resolution. The
challenges there are that the detector still needs >> 44 Mhz response
and has to be able to be gated electrically at a 44 MHz rate.
.

          Russell McMahon

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