You always may rightfully say you're the inventor (or one of several) of a patent issued for something you invented. But you can't "use it" unless you own righ

You always may rightfully say you're the inventor (or one of several) of a patent issued for something you invented. But you can't "use it" unless you own rights to the invention. Patent inventorship and ownership are different things. Most likely, you assigned all rights to your invention to your employer at the time of invention. The patent will name you as the inventor, and your then-employer will have all rights to the invention. Neither you nor your next employer can use the patent unless you negotiate permission from the rights holder (your former employer or whomever they sold the rights to).