Not to throw water on your fire but, here is a product that is very similiar.
http://www.lightwedge.com/prod_paperback.html
A plus that yours has is that is it hands free. However, I noticed in your pictures the border cuts off letters at the edge of the screen. I think I would find that a little annoying.
A plus I find with looking at the lightwedge is that it is more evenly illuminated, with no border.
To the readers out there, I haven't tried either product. These are just my observations from pictures.
Perhaps as you work on refining your product you can take the best ideas from both and combine them for a better product.