Patent ID: 7439692

Claim:
A linear compressor, comprising: a drive motor; a piston reciprocating by the drive motor; and a control unit to generate a reference current having a phase difference of 90° and an equal frequency with respect to a displacement waveform of the piston, and to control a drive current supplied to the drive motor to synchronize with a resonance frequency of the piston by synchronizing the drive current with the reference current, wherein the control unit receives top and bottom dead center commands from an outside of the linear compressor, and sets a maximum amplitude of the reference current so that the drive current is synchronized with the reference current to allow top and bottom dead centers of the piston to satisfy the top and bottom dead center commands, respectively, and wherein the control unit compensates for differences between the commanded top dead center and an actual top dead center of the piston and between the commanded bottom dead center and an actual bottom dead center of the piston.