Active matrix substrate and display device

An active matrix substrate comprising:

• a substrate;
• and
• a plurality of oxide semiconductor TFTs supported by the substrate,
• wherein each of the plurality of oxide semiconductor TFTs includes
• an oxide semiconductor layer including a channel region, and a source contact region and a drain contact region located on a respective one of both sides of the channel region,
• a lower gate electrode disposed between the substrate and the oxide semiconductor layer, and
• an upper gate electrode disposed on the opposite side of the lower gate electrode with respect to the oxide semiconductor layer, and
• in a plan view, when a protrusion width of the lower gate electrode from the upper gate electrode toward the source contact region is referred to as a first protrusion width, a protrusion width of the lower gate electrode from the upper gate electrode toward the drain contact region is referred to as a second protrusion width, and a sum of the first protrusion width and the second protrusion width is referred to as a third protrusion width,
• the plurality of oxide semiconductor TFTs include a first TFT and a second TFT having the third protrusion widths different from each other.