You just take a cardboard box, cut a hole in it, take one of your old round specs stick it in there and make a 6 inch long pipe and stick the second glass piece at the end of it and adjust it back and forth so the focus is sharp when you project it onto the wall.
This don't work very good since your TV wont put out a good enough picture so you can see it properly, but it works... For watching movies etc in a dark room.
Considering a professional projector costs like $4000 or so.. What do you expect for 10 bucks? Which is actually a color LCD screen like your laptop's and a real slide projector behind it will cast a decent picture.
Even those giant screen TV projectors are not very sharp even in a dark room and those cost $3000 on up.
I have seen some cheap Chinese made wall projectors.. But remember, the slide projector uses like a 200 watt bulb which is projecting that light through the LCD screen... I am not sure those Chinese ones will last very long.