I am not an attorney, but if you invent something similar
to a camera, CD, projector, TV, etc. it would be covered by
a patent. Anything you originally record yourself on the
new medium/invention that is not a copy of some other
copyrighted picture, music, writing, etc. would be covered
under copyright laws. If someone else buys and uses
the new medium/invention to make an original copy/recording/etc,
that person has copyright ownership, not the inventor of the
new medium/invention. A patent will protect the new
invention from being duplicated/manufactured by another
person/company.
For example, let's assume a new type of medium similar
to a CD/cassette/etc is invented, along with a new device
that will record on the new medium and to playback any
recordings on the new medium. Patents will cover the medium
and the recording/playing device(s). Copyrights will cover the
contents of any copyrighted recordings put on the new medium.