user10964: I need to detect when a paper comes out from a laser printer and count the number of printed papers. For that I hope to use a PIR sensor to detect the movement of the paper from the printer. Is it possible to detect the movement of a paper using a PIR sensor? Please be kind enough to help me.

user7856: The solution from the OP with the photo-interruptor is probably the most standard one.
However it might be worth checking if you can get away with a light sensor: assuming that the paper is mostly of different colour than the background, the paper should change the current passing through the photodiode.
Alternatively, you could use a proximity sensor, aimed at a location on the path of the paper, where there is typically nothing.
These 2 solutions are trying to avoid having to place something on both sides of the paper. If that doesn't bother you, then I'd recommend the OP's solution.

user4143: If the paper is hot when it comes out of the printer, possibly.  Could be unreliable though.
Better would be to place a photo-interrupter (or IR LED and IR Photodiode) in the path of the paper to detect a break in an infra-red beam.

10964: <p>I need to detect when a paper comes out from a laser printer and count the number of printed papers. For that I hope to use a PIR sensor to detect the movement of the paper from the printer. Is it possible to detect the movement of a paper using a PIR sensor? Please be kind enough to help me.</p>
 7856: <p>The solution from the OP with the photo-interruptor is probably the most standard one.</p>

<p>However it might be worth checking if you can get away with a light sensor: assuming that the paper is mostly of different colour than the background, the paper should change the current passing through the photodiode.</p>

<p>Alternatively, you could use a proximity sensor, aimed at a location on the path of the paper, where there is typically nothing.</p>

<p>These 2 solutions are trying to avoid having to place something on both sides of the paper. If that doesn't bother you, then I'd recommend the OP's solution.</p>
 4143: <p>If the paper is hot when it comes out of the printer, possibly.  Could be unreliable though.</p>

<p>Better would be to place a photo-interrupter (or IR LED and IR Photodiode) in the path of the paper to detect a break in an infra-red beam.</p>
