It might sound futuristic - and it is. The patent isn't about stopping bullets or lasers or anything like that, though. Instead, it detects explosions near a vehicle, and then quickly heats up the air or water that's in between the vehicle and the blast. The heat creates a plasma shield that's more dense than normal air, adding to the vehicle's protection.
This diagram from Boeing shows the different parts of the force field system:
Boeing's patent application shows how the force field technology could work with a military vehicle:
The above diagram shows a military Humvee with a device that can lessen the impact of explosions from bombs like improvised explosive devices (IEDs).
But there could be other uses for Boeing's force field technology. Boeing notes that it can be used in water as well as air, heating up the area around boats or submarines to lessen damage from explosions.
Here's Boeing's full patent filing: