# Has a Light Plane sensor been invented?

1. Feb 10, 2004

### NickC

Has a "Light Plane" sensor been invented?

Hi,

Does a "Light Plane" exist or has one been invented? What I need is a light beam sensor that acts on a plane, showing a difference in voltage if any part is blocked or interferred with.

I'm a college student trying to come up with ways to accurately measure the speed of a ball before & after it has bounced, to calculate the change in kenetic energy. The problem is with a traditional light beam, the readings are only accurate if they go right through the very centre of the ball.

Any thoughts?

Nick.

2. Feb 10, 2004

### chroot

Staff Emeritus
You could use several independent photodetectors in an array, with one conical light source illuminating all of them.

You could use a photovoltaic cell, and measure the current it is producing.

You could use a CCD chip.

- Warren

3. Feb 10, 2004

### chroot

Staff Emeritus
As far as measuring speed, have you considered using ultrasound or radar?

- Warren

4. Feb 10, 2004

### Integral

Staff Emeritus
Do a search on LIGHT CURTAIN. These are relatively common in industry, generally used as safety barriers. Break the "light curtain" shut the equipment down.

I believe that they are simply an array of photo sensors and LEDs.

Edit:

I googled it for you this is Banner there are other manufactures as well.

How much \$ are you willing to spend.

Last edited: Feb 10, 2004