i currently have a provisional patent on a mechanical device. i obtained this through an invention company with which i am currently in contract, however that contract is about to expire. the idea has not yet sold, and i am about to purchase a full legal patent through a patent lawyer. does my current provisional patent protect me enough that i can divulge information about it to prospective buyers? i want to see if i can get some interest in the idea before i pay the fees involved in getting a full patent, but i don't want to overexpose the idea without proper protection. what are my options?