On a few occasions, we have presented incoming business and law students with the following hypothetical. We asked them to identify, without guessing, which if any of the characters in the hypothetical are liable for patent infringement:
Blair Electronics manufactures components for TV sets. In doing so, it infringed upon someone else's patents. This occurred because Blair Electronics copied someone else's component, which was protected by a valid patent. Blair's component was purchased by Tom's Television and was installed in all of Tom's TV sets. These sets were sold to Diane Distributor, who sold them to Roger's Retail. Carl Consumer bought a TV set from Roger's Retail.
Typically, although most students are aware of the infringing manufacturer's liability, only a handful know that liability can be imposed solely for the unauthorized sale or use of the patented invention, which means that Tom, Diane, Roger, and even Carl (assuming he turns on the set) are all liable.
In fact, as we noted in Chapter 2, patent law confers upon the patentee a right to exclude others not only from the unauthorized manufacture, but also from the unauthorized sale, offer of sale, use, or importation of the patented invention. By rendering all unauthorized uses of the patented product unlawful, patent law departs from the practice found in trade secret, copyright, and trademark law, all of which proscribe only some unauthorized uses of protected material.