Pizza trays and patents

I saw three patents listed on the inside of a thin cardbord tray that held one of the Wegmans individual frozen french bread pizzas that I like. I figured people were being greedy and patented the paper tabs that held this small tray together or something silly like that, but there's actually a lot of technology in that tray... First of all, there's a thin conductive layer on the bottom of the tray which is engineered to absorb energy and cause the pizza to toast more on the outside. There is also a network of "fuses" made from grids of more conductive material which helps the pizza cook evenly and also similarly in different microwaves. When too many microwaves hit a particular area of the tray, the network breaks down in that area causing the tray to heat up a little less. Granted I doubt this all has a huge effect, but the patents are much niftier than I thought they'd be.