So I've been making IR pens for my Computer Science class and getting incredibly interested in the whole idea. So I built a good pen in which the IR LED was touching the screen. This became a pain when I had to constantly hold the pen at awkward angles to get it to work. This problem bugged the living snot out of me. so I went and built a pen with the IR light in the rear of the pen instead of the front. this allows you to have the momentary switch at the front of the pen to make it so it turns on when you touch the screen. so I wanted to display this idea because I think others would be interested.
sorry about the image quality. my camera is an really old.

freezetech
A few have tried this idea, the only problem is , that is is dependant on the angle you hold the pen, most noticable on a projected image, when writing down low.

I use a IR-Led on the tip of my pen with no problems, I only need to rotate my body a few degree out to ensure the Wiimote can see my pen.

Which IR-led are you using? If you use the Vishay TSAL6400 you will find your IR-Led tip problems will be resolved.

Benpaddlejones

I'm currently using a radio shack IR LED. which isn't worth the money I spent on it. I'm waiting for some vishnay TSAL 5300's to come in. but I've used it, and had no problems when it comes to angle if you hold it the same way you hold a pen even on a projected surface. its best for this design to have the wiimote up higher to the side you are handed. so I had mine up to the left, because I'm left handed. the reason I posted it was because I hadn't seen it any where in the forms else wise.

freeztech
Interesting, how does it go writing?

Benpaddlejones

it works great writing. I am going to go to radioshack soon and buy a different switch and see if that one works any better. The big thing is that you can't use your hand for writing. you have to move the entire hand as a unit when you write but as it turns out when using this as a projected image most people write that way anyway.

it just comes down to you have to write deliberately.

freezetech
I suggest a Micro SPDT switch or a tactile switch. Both require much less force to action. Personally I prefer the Micro SPDT mine is turned so the leaver points down to the tip of the pen allowing me to get a very natural hand position and it has a bend on the end of the leaver that my finger sits on nicely.

Benpaddlejones

yeah. thats what I was going to get. the tip i had worked fine for projecting on the wall. but one of those switches will work much better. Most of my ideas are incredibly spontaneous so I end up building them out of what is on hand hence the jerry-rigged battery compartment. So when I get out to radio shack I will put a better switch in with the Vishnay LED. Making a good pen.