ir emmitter detector

in the ir emmitter circuit for some reason they have either an npn or a pnp transistor. when they have an npn transistor the arrow is pointing away from the ir emmitter.

how in the world does this suposed to help amplify the signal?

Your question does not make sense without attaching a schematic of your circuit.

I'm not sure quite what you mean either. But here are the configurations for transistors if that is what you are after.

For balckbunny!
Arrow shows the path that current flows. In the last picture in shadymans if you connect a resistor to the collector to VDD + & take the output from the collector to another IC.

When the transistor in OFF condition there’s no current flows through the collector to emitter. So you can see the logic HIGH in the collector output.

If the transistor ON then the current flows through the collector to emitter. So the logic at collector can determine to LOW mostly the voltage between collector and emitter falls to 0.7V or less.

This can see vise versa if you take signal from the emitter output to the next IC.

You need to study some basic transistor theory. A transistor has three leads, any one of which can be grounded to amplify a signal, and with different results (current and/or voltage amplification)

try
http://amasci.com/amateur/transis.html

thank you all for your help.

however i have no clue how in the world this ir emitter signal is amplified

**broken link removed**

obviously Ie=Ic+Ib. but the led is conneted to the collector pin. how is it amplified?

It's a standard common emitter amplifier, the most common type there is.

The transistor has a high current gain.
A small base current results in a large collector current.
The emitter current is also large.