You can print digital negatives onto an inkjet transparency easily enough, people use this technique for making contact prints with, for example cyanotype like processes. Obviously this means a 1:1 ratio with the final print.
I was thinking along the same lines a while back and after a bit of googling it would seem that whilst enlarging is certainly possible the quality isn't great, but bigger the negative the better. So you need to be thinking of a 4x5 enlarger I would think.
The modern method uses printers such as
this to digitally expose the paper with lasers.