outlet 12 a vent outlet 13 and a heat outlet 14 that are provided in a branched fashion and all open to a vehicle compartment two mode doors 15a 15b are disposed at the junction between the vent outlet 13 and heat outlet 14 and the junction between the heat outlet 14 and the defroster outlet 12 the mode doors 15a 15b are actuated by actuators 16 17 respectively to set a desired discharge mode of the air conditioner the evaporator 8 is in fluid communication with a variable displacement compressor 18 a condenser 19 a liquid tank 20 and an expansion valve 21 to jointly constitute a refrigeration cycle or system for cooling air passing around the evaporator 8 the variable displacement compressor 18 is of the swash plate type for example the swash plate type variable displacement compressor 18 includes as shown in fig4 a drive shaft 24 disposed in a compressor body 25 and coupled to an engine 22 fig3 via an electromagnetic clutch 23 fig3 and a swash plate 26 mounted on the drive shaft 24 by a hinge ball 27 the swash plate 26 thus mounted on the drive shaft 24 oscillates or swings about the hinge ball 27 within a crank chamber 28 so that at least one piston 29 connected to the swash plate 26 is reciprocated in a cylinder bore 30 in response to the oscillation of the swash plate 26 the variable displacement compressor 18 further has a pressure control valve 31 facing the crank chamber 28 the pressure control valve 31 includes a movable valve element 33 movable for adjusting the degree of communication.