Patent ID: 7210911

Claim:
A controller for a variable displacement compressor, the controller comprising: a cooling load detecting means for detecting cooling load; a cooling load controlling means for controlling displacement of the compressor so that the load detected by the cooling load detecting means is converged to a predetermined load setting; a discharge pressure detecting means for detecting the pressure of a discharge pressure region; a discharge pressure controlling means for controlling the displacement of the compressor so that the pressure detected by the discharge pressure detecting means is converged to a predetermined discharge pressure setting; and a switching means for switching control of the compressor between the cooling load controlling means and the discharge pressure controlling means in accordance with the pressure detected by the discharge pressure detecting means, wherein the switching means switches the control of the compressor from the cooling load controlling means to the discharge pressure controlling means when the pressure detected by the discharge pressure detecting means is greater than a threshold pressure, which is set greater than or equal to the discharge pressure setting.