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Kwang Bok
Kwang Bok Kim, Daejeon KR
| Patent application number | Description | Published |
|---|---|---|
| 20100194295 | Field Emission Device - The present invention relates to a field emission device. More specifically, the present invention may prohibit unnecessary voltage from being applied to an anode electrode during non-operating time that no voltage is applied to a gate electrode to reduce driving power, prohibit electrons from being emitted with unnecessary high voltage which is applied to the anode electrode to increase luminous efficiency, and reduce a time that unnecessary high voltage is applied to the anode electrode to extend life time of the field emission device, by applying AC voltage to the anode electrode to correspond to a time that voltage is applied to the gate electrode and a type of voltage which is applied to the gate electrode. Therefore, the present invention comprises a front substrate and a rear substrate which are disposed at a certain distance and opposite to each other; at least one or more cathode electrodes formed on said rear substrate; at least one or more gate electrodes formed to be distant from said cathode electrodes and to be insulated with said rear substrate; emitters formed on the upper surfaces of said cathode electrodes; an anode electrode formed on said front substrate toward said rear substrate side; a fluorescent layer formed on said anode electrode; a first voltage application means for applying an AC voltage to said anode electrode; and a second voltage application means for applying an AC voltage to said gate electrode, wherein the AC voltages being applied to said anode electrode and said gate electrode are synchronized. | 08-05-2010 |
| 20110037400 | Constant Current Driving Circuit for Field Emission Device - A constant current driving circuit for a field emission device has a ground current of an anode electrode measured in real time and the measured ground current is fedback to vary the frequency and duty ratio of a voltage applied to gate and cathode electrodes of the field emission device, thereby causing the ground current of the anode electrode to be constantly maintained. The field emission device has an anode electrode formed on a front substrate, gate and cathode electrodes formed on a rear substrate disposed opposite to the front substrate to be spaced apart from the front substrate by a predetermined distance, and an emitter formed on a top surface of the cathode electrode. The constant current driving circuit includes current detection circuit for detecting a ground current of the anode electrode; an input power unit for applying a driving AC voltage for emitting electrons from the emitter to the gate and cathode electrodes; and a feedback circuit unit for comparing the ground current of the anode electrode detected by the current detection circuit with a predetermined reference voltage to obtain a current variation and providing the input power unit with a frequency signal for varying a frequency of the driving AC voltage or a duty ratio signal for varying a duty ratio of the driving AC voltage in accordance with the current variation. | 02-17-2011 |
Kwang Bok Kim, Seoul KR
| Patent application number | Description | Published |
|---|---|---|
| 20110291142 | OXYNITRIDE PHOSPHOR, METHOD FOR PREPARING THE SAME, AND LIGHT-EMITTING DEVICE - The present invention relates to an oxynitride phosphor, a method for preparing the same, and a light-emitting device. More specifically, the present invention provides the oxynitride phosphor including crystals represented by the following Chemical Formula, a method for preparing the same, and a light-emitting device including the oxynitride phosphor. The invention includes the crystals' represented by the following Chemical Formula to obtain high light-emitting efficiency. [Chemical Formula] (A | 12-01-2011 |
Kwang Bok Lee, Seoul KR
| Patent application number | Description | Published |
|---|---|---|
| 20090034427 | MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION METHOD AND APPARATUS USING THE SAME - A multiple-input multiple-output (MIMO) communication method and apparatus are provided. A MIMO communication apparatus includes a selected beamforming vector determining unit to determine a selected beamforming vector corresponding to a selected user, a performance information generating unit to generate performance information corresponding to where a non-selected beamforming vector is allocated to a non-selected user, and an additional beamforming vector selecting unit to select an additional beamforming vector corresponding to the non-selected user based on the performance information. | 02-05-2009 |
| 20100093361 | APPARATUS AND METHOD FOR TRANSMISSION OF DYNAMIC FEEDBACK CHANNEL INFORMATION IN A MIMO SYSTEM - A base station apparatus and method of transmission of dynamic feedback channel information in a MIMO system. The base station apparatus includes a first channel state information receiving unit to receive a first channel state information; a receiving terminal selection unit to select at least one receiving terminal to receive data from among a plurality of terminals; a quantization length determination unit to independently determine a second quantization length of the selected receiving terminal; a quantization length transmission unit to transmit the second quantization length to the selected e receiving terminal; a second channel state information receiving unit to receive second channel state information from the selected receiving terminal; and a data transmission unit to transmit data to the selected receiving terminal using a plurality of transmission antennas of a base station based on the second channel state information. | 04-15-2010 |
| 20110158335 | UNITARY PRECODING APPARATUS AND METHOD IN MULTI-USER MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) COMMUNICATION SYSTEM - In a multi-user multiple input multiple output (MIMO) communication system using the same radio resource, a unitary matrix may be generated to remove interference signals and enhance a transmission capacity. The unitary matrix may be used for precoding. Vectors included in the unitary matrix may have a most similar direction to precoding vectors of target terminal devices and may be orthogonal to each other. | 06-30-2011 |