Increasing max FOV angle of latest VL5xxx sensors?

[BWies.2]

Enjoyed your nice presentation...

We need almost hemispherical coverage (maybe 160+ degrees etc) for intrusion/prox detection;

we are not power sensitive.

• Are there optical ways of increasing FOV of the latest 60+ degree FOV sensor to well beyond this FOV angle?

• Otherwise, how many sensors might be needed to get reasonable 'dome' coverage? (In this latter case, will sequencing/interleaving sensor inquiries btwn multiple sensors

reduce inter-sensor crosstalk risk? Would this situation require special add'l optics?

FYI, we need to 'read the world' around ~10 X per sec.

Thanks!

Bill Wiese

San Jose CA

[John E KVAM]

The problem with increasing the FoV is that you are spreading the light, and there is only so much of it. So what you end up doing is reducing the distance at which the sensor can range.

There are 3 areas customers wish we could improve. These are 1) distance at which we can range, 2) the Field of View, and 3) the power consumption.

Unfortunately, enlarging either of the first two, increases the power consumption.

We are working on a wider FoV, but as the power is fixed, the distance is going to have to go down.

So to your problem.

If you place the sensors 45 degrees to each other, 4 of them will cover the a 180degree swath by 45 degrees.

To cover an entire hemisphere would take a lot.

I had one researcher use 9 of them. But using 3 sensors to cover the 180 degees would leave some gaps in the coverage.

Luckly he was looking for people moving and it's difficult to move around and stay in those gaps.

You can play around with a looking for a configuration. One does not need to see an entire body to know someone is there.

And that increases the effective FoV somewhat.

And leaving a bit of a gap in your coverage does solve any interferrence problems you might have if the sensors overlap.

The other thing to consider is the bandwidth. Each collect can generate 2000 bytes of data if you turn on all the options. And with as many as 9 sensors and 10X per second thats a lot of data.

You are going to need multiple I2C busses.

• john

[BWies.2]

John,

Thanks.

Disappointing. We'd love to use such a sensor but the FOV is a concern. # of sensors is an issue too; we could actually

allow gaps in coverage near the 'protected item' as long as 'beam convergence' could protect further out - if we can get an

intruder further out we don't care about closer. We are not worried about 'whole body' detection but hand entry at up

to 2 - 2.5 ft max.

We also are not worried at all about power consumption (it's a powered product, no batteries, etc.). I suspect

you may eventually evolve parts line variants for powered apppliances with no concern re: battery life.

Did you see my other question below with title of "static object removal"?? Appreciate guidance.

Bill Wiese

San Jose CA

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