Design patents are a type of patent issued under United States of America law. (Other locations have similar protections but they are called different things.) The patent is granted based on the unique appearance or concept of an item rather than its "usefulness". Design patents typically are sought for items where the appearance is as - or more - important than the underlying craftsmanship itself. So, things like jewelry, toys, furniture, car parts, etc. are frequently granted design patents.
Design patents have a life in the US of fourteen years from the date of issuance. Their main usefulness is as a supplement to copyright protections. Whereas someone claiming a copyright in a work can prevent actual copies being made, a design patent can more easily be used to prevent the unauthorized creation of similar items which are not actually copies. Neither protection is absolute, but some counsel believe that having both is important where even the hint of similar design is a threat to the value of the original design.
From 1978 through 1987, Paramount Pictures sought and obtained various design patents for Star Trek designs. There seem to have been no other filings after 1987, and Paramount's legal department instead probably feels comfortable with existing copyright protections.
In each instance of a design patent at least one "inventor" has to be listed. The inventor can never be the corporation, it has to be an individual or individuals. It is sometimes interesting to see who gets credit for what on the official documents.
Did You Know that the carpets on the bridge of The Next Generation were changed nearly every season? In the first season, they were an Earthy tan and orange, but were later changed to various shades of blue and dark orange.