Retroreflective Sensors, Reflectors

Reflective Tape Vs. Prism Reflectors

If you use reflective tape, you will not get the reliable results that a prism type reflector will give you. Prism reflectors have rows and rows of little prisms inside. They act like a pinball machine for light. When light hits the reflector, from all angles, it bounces around those prisms just like a pinball, until eventually it gets directed back toward the receiver lens. Far more light gets returned from its source; that's why the range for reflectors is much greater than for reflective tape.

Prism Reflectors:

Reflectors come in oval shapes or rectangular shapes, and in many sizes. They are not at all expensive, and it is advisable to get a reflector with your retroreflective sensor, as opposed to using tape. Light can hit the reflector from all angles. No matter what direction it comes from, the prisms will help direct as much emitted light as possible back to its source.

Polarizing Light

Prism reflectors serve another valuable service. They polarize the light. They turn it on its plane. Reflective tape cannot do this. Polarizing the emitted light becomes a very important factor in reliable retroreflective sensing, as you'll see in a slide coming up.

Summary:

When light hits a prism type reflector, the prisms polarize (turn) the light and help direct it back to the sensor. More range, polarized light! Stay tuned!