IR Sensors

Projects General Guidance
1

Hi,

I am looking to create a sensor device that can detect and edge of a paper. For example say we have a plain surface with a 1mm black line and if a piece of paper was to cross this line then an LED should flash.

Would anyone know if there is a IR sensor that would suit this type of scenario where precision is key. From what I have read, IR phototransistors are mentioned – has anyone had any experience in using such a sensor with the Arduino or should I be reading into some other type of sensor?

Many thanks

2

https://www.aliexpress.com/item-img/10PCS-IR-Infrared-Line-Track-Follower-Sensor-TCRT5000-Obstacle-Avoidanc-For-Arduino/32673376693.html?spm=2114.10010108.1000017.2.3fa4ea0fxLiVAx

I've used these for line following and found them very reliable. It is quite sensitive to the distance from the object. (10mm) But it is very good at recognising black and white objects.

3

Use VL53L0X sensor it is very good if range is 300mm to 500mm (~19 inches ) between sensor and the object. After that range the beam will spread and it will cause problem

4

Would these sensor detect a piece of paper if it were to cross a 1mm line?

5

rayholt:
I am looking to create a sensor device that can detect and edge of a paper. For example say we have a plain surface with a 1mm black line and if a piece of paper was to cross this line then an LED should flash.

There are multiple ways to detect this.

  • detect a lessening of reflected light
  • detect thickness of the paper
  • detect loss of signal from IR (or other) xmit/rcv pair

What is it you're actually wanting to sense? What's the significance of the black line?

6

Thanks. You see I am working on a project that has a motor which drives a piece of paper from point A to point B. The paper will travel through a paper creaser.

The 1mm line is important to ensure that it is perfectly aligned.

I've also read up on IR phototransistors, though not sure whether this would be the best way forward.

Would your suggestions still work based on this scenario?

dougp:
There are multiple ways to detect this.

  • detect a lessening of reflected light
  • detect thickness of the paper
  • detect loss of signal from IR (or other) xmit/rcv pair

What is it you're actually wanting to sense? What's the significance of the black line?

7

rayholt:
The 1mm line is important to ensure that it is perfectly aligned.

If you can mount a sensor at each side of the paper, a photo interupptor (IR xmit/rcv pair) could work.

                  |         |
                  |         |
                  |         |
   interruptor 1 >|---------|< interupptor 2

leading edge of paper ^