Copyright law is a minefield and varies from Country to Country.
Before entering in to any form of contract etc... seek legal advice. Get the company to sign a legally binding NDA before giving any specifics.
Alternately ask around and put your own team together (again NDA) develop a demo then patent/copyright? Then you can go to the big companies/distribution houses or even get some investment and do it yourself. Make sure they are citizens of a Country that can be governed by our laws!
Hope that helps
