Abstract: A system for controlling a linear compressor, generates freezing force as a piston reciprocates according to rotation of a motor which receives alternating current power through a triac. The system includes a controller which moves up or delays a trigger signal corresponding to an absorption cycle or a compression cycle, such that the center point of the piston reaches a resonant point when a current and a phase difference of the motor deviate from predetermined ranges.

Abstract: An operating system of a liquefied natural gas ship for performing sub-cooled liquefaction of boil-off gas includes a boil-off gas compressor, a cryogenic heat exchanger connected to a refrigerator system, and a first check valve and a first pressure control valve, installed in a pipe between a liquefied natural gas phase separator and a gas combustion unit, and a second check valve and a second pressure control valve, installed in a parallel pipe connected to the pipe in parallel. The parallel pipe is connected to a pipe between the boil-off gas compressor and the cryogenic heat exchanger such that boil-off gas is supplied to an upper vapor region of the liquefied natural gas phase separator. Thus, pressure and level of the liquefied natural gas phase separator are stably controlled. Power consumption is effectively reduced, and economical efficiency is achieved by stable operating pressure and level of the liquefied natural gas phase separator.

Abstract: A backlight unit suitable to prevent color separation phenomenon of LED lamps is disclosed. The backlight unit includes a bottom cover, a printed circuit board attached to an inner upper surface of the bottom cover, a plurality of LED lamps mounted on an upper surface of the printed circuit board to extend in a direction, and a reflecting plate having a plurality of holes to expose light emitting portions of the LED lamps, respectively, the holes having a tapered side section.

Abstract: A backlight assembly includes a plurality of light emitting diode units, each of the plurality of light emitting diode units including at least one light emitting diode and a printed circuit board mounting the at least one light emitting diode, and a reflective sheet on the printed circuit board, the reflective sheet having at least one hole corresponding to the at least one light emitting diode, such that the at least one light emitting diode is exposed through the hole, wherein the plurality of light emitting diode units are spaced apart and are electrically connected to each other via at least one line extending from the printed circuit board, the at least one line is bent toward a predetermined direction.

Abstract: An operating system of a liquefied natural gas ship for performing sub-cooled liquefaction of boil-off gas includes a boil-off gas compressor, a cryogenic heat exchanger connected to a refrigerator system, and a first check valve and a first pressure control valve, installed in a pipe between a liquefied natural gas phase separator and a gas combustion unit, and a second check valve and a second pressure control valve, installed in a parallel pipe connected to the pipe in parallel. The parallel pipe is connected to a pipe between the boil-off gas compressor and the cryogenic heat exchanger such that boil-off gas is supplied to an upper vapor region of the liquefied natural gas phase separator. Thus, pressure and level of the liquefied natural gas phase separator are stably controlled. Power consumption is effectively reduced, and economical efficiency is achieved by stable operating pressure and level of the liquefied natural gas phase separator.

Abstract: A linear compressor having a core combined to one end of a piston to detect a position of the piston reciprocally moving up and down, and a bobbin having a first sensor coil and a second sensor coil that detect the position of the core. A controller determines the state of a load on the piston by measuring the time the core takes to exit and enter the bobbin from an inhale stroke through a compression stroke of the piston and control a position of the piston based on the measured state of the load. A method for controlling the operation of the linear compressor including timing the core driven by a piston through a stroke cycle, receiving the time and computing a load on the piston, outputting a piston position signal based on the load computed, and controlling a piston stroke according to the piston position signal, by varying the power driving the linear compressor.

Abstract: A linear compressor control apparatus including a position detecting unit to detect the position of a piston and a compensation unit to compensate for output distortion of the position sensor. The compensation unit compensates for output distortion of the position sensor, caused by internal temperature of the linear compressor and load variation. Further, the compensation unit separates a high frequency signal and a DC signal from the output of the position detecting unit, and simultaneously performs position and temperature detecting operations using the separated high frequency signal and the DC signal.