Active matrix substrate and demultiplexer circuit

An active matrix substrate comprising:

• a display area including multiple pixels;
• a non-display area provided in a vicinity of the display area;
• a substrate;
• a demultiplexer circuit positioned on the non-display area and supported on the substrate;
• multiple source bus lines extending in a first direction in the display area;
• and
• multiple gate bus lines extending in a second direction that intersects the first direction, in the display area,
• wherein the demultiplexer circuit includes multiple TFTs and is connected to the multiple source bus lines,
• wherein each of the multiple TFTs includes
• a gate electrode,
• an oxide semiconductor layer positioned in such a manner as to face the gate electrode with a gate insulation layer in between, the oxide semiconductor layer including a source contact area, a drain contact area, and an area between a source and a drain, which is positioned between the source contact area and the drain contact area and includes a channel region,
• a channel protection layer that covers only a portion of the area between the source and the drain, of the oxide semiconductor layer,
• a source electrode that is brought into contact with the source contact area of the oxide semiconductor layer, and
• a drain electrode that is brought into contact with the drain contact area of the oxide semiconductor layer, and
• wherein, at a certain cross-section in a channel length direction, of each of the multiple TFTs, an end portion facing toward the channel region, of one electrode of the source electrode and the drain electrode is brought into contact with the channel protection layer, and an end portion facing toward the channel region, of another electrode is positioned at a distance away from the channel protection layer.