Abstract: A level shifter includes: a voltage dividing unit receiving a first voltage and an input voltage, and generating a middle voltage between the first voltage and the input voltage; first and second voltage compensating units connected to the voltage dividing unit and connected between the first voltage and a second voltage, for compensating a voltage variation of the voltage dividing unit; and an output unit receiving an output from the voltage dividing unit and generating an output voltage.

Abstract: Provided is a low power random bit generator utilizing a multiplying digital to analog converter (MDAC) which is used in a switched capacitor amplifying circuit and an analog to digital converter with a pipeline architecture. The low power random bit generator includes: an MDAC, outputting a predetermined analog voltage formed by using a ground voltage, a reference voltage, an initial voltage and a digital signal; a comparator, outputting a direct current (DC) voltage determined by comparing the analog voltage with the ground voltage; and a data storage unit, storing a predetermined digital signal corresponding to the DC voltage, and outputting the digital signal.

Abstract: A display device includes a circuit board provided with signal lines, a first and a second panel unit separately attached to the circuit board and each provided with pixels comprising switching elements, and a driving circuit chip mounted on the circuit board and driving the first and the second panel units.

Abstract: An analog buffer, display device having the same and a method of drving the same are provided. The analog buffer applies an analog voltage to a load. The analog buffer includes a comparator and a transistor. The comparator is configured to compare an input voltage provided from an external device with the analog voltage applied to the load. The transistor is turned on to electrically charge the load when the analog voltage is lower than the input voltage or turned on to electrically discharge the load when the analog voltage is higher than the input voltage, and turned off when the analog voltage becomes substantially the same as the input voltage.

Abstract: Disclosed are an air conditioner in which one or more compressors are operated so that the refrigerant compression capacity of the operating compressor(s) is variably changed in accordance with a cooling or heating load for cooling or heating air in a room, and a method for controlling an electronic expansion valve of the air conditioner.

Abstract: Disclosed is a method for controlling noise reduction of an air conditioner comprising the steps of: (a) stopping a compressor, when the air conditioner is stopped under the condition that the compressor and an outdoor fan are operated; and (b) stopping the outdoor fan after a designated time after a point in time when the compressor is stopped in the step (a) elapses, thus reducing the size and duration of noise generated by the flow of the refrigerant due to a difference of inner pressures in the air conditioner and allowing the noise at a designated frequency band generated by the flow of the refrigerant, which causes unpleasantness to users, to be concealed by noise generated by the operation of the outdoor fan. Accordingly, the method of the present invention increases reliability of air conditioner products.

Abstract: A TFT array panel is provided, including an insulating substrate, gate lines horizontally provided on the insulating substrate, data lines isolated from the gate lines and intersecting the gate lines, a pixel electrode in a pixel region defined by intersecting the gate lines and data lines, a TFT for transmitting or intercepting an image signal transmitted through the plurality of data lines to the pixel electrode in response to a scanning signal transmitted from the plurality of gate lines, a transmission gate for distributing the image signal input from an input line to the plurality of data lines, and a repair line intersecting the input line of the transmission gate. Therefore, since the input repair line and the input line of the transmission gate are intersected, a parasitic capacitance occurring between the repair line and the input line of the transmission gate can be reduced.

Abstract: An amplifier includes a biasing section, first and second differential amplifying sections and an output section. The biasing section outputs first and second bias currents based on first and second power source voltages. The first differential amplifying section outputs a first amplified voltage based on the first bias current. The second differential amplifying section outputs a second amplified voltage based on the second bias current. The output section outputs the second power source voltage based on the first amplified voltage and the first power source voltage, and outputs the first power source voltage based on the second amplified voltage and the second power source voltage. Therefore, a variation of the threshold voltage is compensated to enhance display quality.

Abstract: A method for controlling operations of an air-conditioner includes: a step in which when an operation load of an air-conditioner increases, if an outputted compressing capacity of the air-conditioner is smaller than a compressing capacity corresponding to the operation load and an operation frequency of the first compressor is a maximum frequency of the first compressor, a second compressor is operated; and a step in which when the operation load is reduced, if the outputted compressing capacity of the air-conditioner is greater than the compressing capacity corresponding to the operation load and the operation frequency of the first compressor is a minimum frequency of the first compressor, the second compressor is stopped.

Abstract: Disclosed are an air conditioning system with two compressors and a method for operating the same, so as to variably change a compression capacity of a refrigerant according to the variation of cooling load. Herein, when a full operation order is inputted to the two compressors in order to satisfy increased cooling load, the first compressor is first operated, and then the second compressor having a compression capacity of a refrigerant smaller than that of the first compressor is additionally operated, so that a current peak value for operating the compressors does not exceed an allowable current range of a circuit breaker installed in a home or building, thereby safely controlling the air conditioning system and simultaneously allowing the current to be provided to other electric appliances, thus improving users' convenience.

Abstract: Disclosed are compressor-controlling device and method for an air conditioner comprising a plurality of compressors. In case several compressors selected from the plural compressors are stopped for a long period of time according to cooling or heating load, the refrigerant contained in a higher-pressure state inside of the stopped compressors moves toward a refrigerant pipe of a lower-pressure inlet port, and oil used to operate the compressors leaks toward the inlet port, thus lowering the oil level within the stopped compressors. Since the stopped compressors are operated during a second designated time when stopped time of the stopped compressors exceeds a first designated time, the stopped compressors are protected from damage due to poor lubrication.

Abstract: Disclosed are an air conditioner for cooling or heating air in a room by compressing, condensing, expanding and evaporating a refrigerant, and a method for controlling an electronic expansion valve of the air conditioner. The air conditioner includes a plurality of compressors, for compressing a refrigerant, of which one or more are operated so that refrigerant compression capacity is variably changed according to the variation of a cooling/heating load; and an electronic expansion valve adapted to control the refrigerant compression capacity. The electronic expansion valve controls the flow rate of the refrigerant after one or more of the compressors are stopped, thereby rapidly achieving the pressure equilibrium at inlet and outlet pipes of the stopped compressor(s), shortening a time taken to allow the stopped compressor(s) to be re-operated, and improving reliability in operating the compressors.

Abstract: Disclosed are an air conditioning system, in which the total operating capacity of compressors is variably controlled in accordance with a cooling or heating load in a room, and a method for controlling the air conditioning method, thus improving comfortableness in the room, reducing an electric power consumption rate, and increasing cooling or heating efficiency. The air conditioning system includes an indoor heat exchanger for cooling a room by heat-exchanging a refrigerant with air in the room; an outdoor heat exchanger for condensing the refrigerant; a plurality of compressors for compressing the refrigerant; and a control unit for controlling operation of the plural compressors in accordance with the cooling or heating load in the room.

Abstract: Disclosed are an air conditioner, which reduces an electric power consumption rate and rapidly copes with the requirements of a user, and a method for operating the air conditioner in a cooling mode for cooling air in a room by an independent or simultaneous operation of small-capacity and large-capacity compressors in accordance with the variation of a cooling load.

Abstract: Disclosed is a method for operating a plurality of compressors of an air conditioner in accordance with a cooling or heating load in a room, in which a power supply unit for supplying power to the compressors is protected when a cooling or heating load in a room is the highest grade. The method comprises the steps of: (a) determining the cooling or heating load in the room; and (b) sequentially operating the plural compressors when it is determined as a result of the step (a) that the cooling or heating load in the room is in the highest grade.

Abstract: An air conditioning system and a method for operating the air conditioning system, in which a plurality of compressors are simultaneously or selectively operated, based on the difference between a room temperature and a desired temperature generated during a waiting time for re-operation of the compressors. The room temperature varying during the waiting time for the re-operation of the compressors maintained at a stopped state is sensed to determine whether or not an increase in cooling load occurs. Based on the amount of the cooling load, it is determined whether the compressors have to operate simultaneously or selectively. That is, the refrigerant compression capacity of the air conditioning system is determined by reflecting the cooling load caused by a variation in room temperature occurring during the waiting time for re-operation taken until any compressor maintained in a stopped state is re-operated.

Abstract: Disclosed are an air conditioning system with two compressors so as to shorten standby time for re-operating a stopped compressor and variably change the compression capacity of a refrigerant according to cooling load, and a method for operating the air conditioning system. The method for operating the air conditioning system with two compressors, comprises the first step of simultaneously operating the compressors regardless of cooling load at an early stage of the operation, the second step of selectively operating one of the compressors according to the cooling load, and the third step of additionally re-operating the stopped compressor when the operated compressor selected from the compressor in the second step is continuously operated for longer than a designated time, thereby shortening the standby time for re-operating the stopped compressor, rapidly changing the compression capacity of the refrigerant according to the cooling load, and improving users' comfort within a room.

Abstract: Disclosed are a heat pump air conditioning system comprising an additional heater and a method for operating the same, in which the additional heater is driven during a full activation standby time taken to simultaneously operate all of a plurality of compressors so as to rapidly satisfy an increased heating load. When the increased heating load exceeding a total capacity of some compressors selected from the plural compressors is sensed, since the additional heater is driven during the full activation standby time so as to rapidly satisfy the increased heating load, the air conditioning system improves heating effectiveness and uniformly maintains room temperature, thereby improving users' comfort.

Abstract: Disclosed are an apparatus and a method for controlling the operation of an air conditioner, in which one or more compressors are operated so that the total refrigerant compression capacity of the operating compressors is variably changed according to a cooling or heating load to be eliminated, and an opening degree of an electronic expansion valve is controlled between minimum and maximum values set according to the total refrigerant compression capacity of the operating compressors, thus stably operating the air conditioner and preventing the refrigerant in a liquid state from being introduced into the compressors and the compressors from overheating.

Abstract: Disclosed are an apparatus and a method for controlling the operation of an air conditioner, in which one or more compressors are operated so that the total refrigerant compression capacity of the operating compressors is variably changed according to a cooling or heating load to be eliminated, and an opening degree of an electronic expansion valve is controlled between minimum and maximum values set according to the total refrigerant compression capacity of the operating compressors, thus stably operating the air conditioner and preventing the refrigerant in a liquid state from being introduced into the compressors and the compressors from overheating.