Patent application number | Description | Published |
20090269051 | METHOD OF CONTROLLING OPTICAL OUTPUT POWER AND PASSIVE OPTICAL NETWORK SYSTEM USING THE SAME - Provided are an optical output power control method that provides optical communication without harming the human body even when a transmission line is cut or no optical network unit (ONU) accesses a communication system, and a passive optical network (PON) system using the method. In the method, an optical signal having a predetermined period is transmitted when an optical communication system is in an abnormal state, wherein the predetermined period includes a laser-on time interval in which the optical signal has a normal power level and a laser-off time interval in which the optical signal is off or has a power level lower than the normal power level, so that the optical communication system performs optical communication without harming the human body even during the abnormal state. | 10-29-2009 |
20090269066 | Single-Unit Integrated Transceiver Having Pump Source and Transceiver Module Using the Same - Provided are a sing-unit integrated transceiver having a pump source and a transceiver module using the transceiver. The single-unit integrated transceiver includes: an optical transmitter converting an input electric signal into a downstream optical signal; an optical receiver converting a received upstream optical signal into an electric signal; the pump source amplifying the downstream or upstream optical signal using a gain medium positioned in an optical transmission line to amplify an output optical signal; a convergence unit arranging or converging the downstream and upstream optical signals to/from the optical transmission line; and a multiplexing and/or a demultiplexing filter, the multiplexing filter positioned on an optical path between the optical transmitter/pump source and the convergence unit, and multiplexing the downstream optical signal and the amplified optical signal to pass to the convergence unit, the demultiplexing filter positioned on an optical path between the convergence unit and the optical receiver and demultiplexing the upstream optical signal to pass to the optical receiver. | 10-29-2009 |
20100003035 | LASER DIODE HAVING AN ABRUPT TURN-ON, OPTICAL TRANSMITTER DEVICE USING THE SAME LASER DIODE AND OPTICAL COMMUNICATION APPARATUS - Provided are a laser diode which has low power consumption and can realize a high on/off extinction ratio by small variation of current and which can modulate optical signals at high speed, an optical transmitter, and an optical communication apparatus including the optical transmitter. The laser diode having an abrupt turn-on characteristic, comprises: an active region in which light is generated by application of current and gain is controlled; and an absorption region absorbing light generated in the laser diode at a current lower than an abrupt threshold current that is the same as or lower than an operation current, the operation current being a current level that allows the laser diode to generate a target optical power, wherein the output optical power rapidly increases at the abrupt threshold current. | 01-07-2010 |
20100008379 | DYNAMIC BANDWIDTH ALLOCATION DEVICE FOR AN OPTICAL NETWORK AND METHOD THEREOF - A dynamic bandwidth allocation (DBA) device and a method thereof are provided. In the DBA method, the band allocation periods according to class queues and allocable bands with respect to each class queue are calculated on the basis of the service level agreement information and stored according to the service types in separate tables. The bandwidth allocation amount is calculated with respect to class queues which have the allocation periods by concurrently checking all the tables at each frame. The upward bandwidth usage efficiency is improved by calculating the final bandwidth allocation information from the service with a high priority order on the basis of the total allocable bandwidth of the corresponding frame. The upward bandwidth allocation amount can be calculated at each frame by reducing the processing speed in calculating the bandwidth allocation amount of each class queue. Accordingly, it is possible to effectively use the network. | 01-14-2010 |
20100272437 | TDMA PASSIVE OPTICAL NETWORK OLT SYSTEM FOR BROADCAST SERVICE - Provided is a TDMA (time division multiple access) PON (passive optical network) OLT (optical line terminal) system for a broadcast service, including packet processor determining information according to types of frames (unicast, multicast, and broadcast frames) and a switch output port using header information (an IP address of a packet header, MAC (medium access control) addresses of Ethernet frames, and the like) of data received from an external node or the ONT (optical network terminal) and attaching the information to header parts of the frames to generate second data, a switch copying the second data by a predetermined number of times according to a transmission method and transmitting the second data to a corresponding destination output port according to the identification codes, M TDMA PON MAC processors removing the identification codes added to the second data and converting the second data into TDMA PON frames, and M optical transceivers converting the TDMA PON frames into optical signals and transmitting the optical signals to an ONT. | 10-28-2010 |
Patent application number | Description | Published |
20080319157 | METHOD FOR PRODUCING NORBORNENE MONOMER COMPOSITION, NORBORNENE POLYMER PREPARED THEREFROM, OPTICAL FILM COMPRISING THE NORBORNENE POLYMER, AND METHOD FOR PRODUCING THE NORBORNENE POLYMER - Disclosed is a method for producing a norbornene monomer composition, a norbornene polymer produced using the norbornene monomer composition, an optical film including the norbornene polymer, and a method for producing the norbornene polymer. The method includes reacting a reaction solution that contains cyclopentadiene, dicyclopentadiene, or a mixture of cyclopentadiene and dicyclopentadiene, an acetate compound, and a solvent so that a content of an exo isomer is 50 mol % or more. Variables such as a reaction temperature, a reaction time, a molar ratio between reactants, and addition of a solvent are controlled so that the exo isomer is contained in content of 50 mol % or more. Accordingly, it is possible to industrially produce an acetate norbornene addition polymer by using the acetate norbornene monomer composition containing the exo isomer in content of 50 mol % or more. | 12-25-2008 |
20090092769 | METHOD FOR POLYMERIZING CYCLOOLEFIN POLYMER CONTAINING POLAR FUNCTIONAL GROUPS AND ELECTRONIC DEVICES EMPLOYING THE POLYMERIZED CYCLOOLEFINS - Disclosed is a method for preparing a cycloolefin polymer containing polar functional groups, comprising: preparing a catalyst mixture including i) a precatalyst, containing a Group 10 transition metal having a ligand containing oxygen ions bonded to the metal; ii) a first cocatalyst which is an organic compound containing a Group 15 element; and iii) a second cocatalyst which is capable of providing an anion and weakly coordinating to the metal of the precatalyst; and subjecting a monomer solution comprising a norbornene-based compound containing a polar functional group to an addition polymerization reaction in the presence of an organic solvent and the catalyst mixture, at a temperature of 80-200° C., the total amount of the organic solvent being 50-800% by weight based on the total weight of the monomer contained in the monomer solution, and the product yield of the polymer being 50% by weight or more based on the total weight of the monomer. | 04-09-2009 |
20090192277 | Method of producing cyclic olefin polymers having polar functional groups, olefin polymer produced using the method and optical anisotropic film comprising the same - A method of producing a cyclic olefin polymer having a polar functional group and a high molecular weight with a high yield in which a catalyst is not deactivated due to polar functional groups, moisture and oxygen is provided. According to the olefin polymerization method, deactivation of a catalyst due to polar functional groups of monomers can be prevented, and thus a polyolefin having a high molecular weight can be prepared with a high yield, and the ratio of catalyst to monomer can be less than 1/5000 due to good activity of the catalyst, and thus removal of catalyst residues is not required. | 07-30-2009 |
20100036071 | Method of polymerizing cyclic olefins and vinyl olefins, copolymer produced by the method and political anisotropic film comprising the same - A method of copolymerizing cyclic olefins and polar vinyl olefins, a copolymer produced by the method, and an optical anisotropic film including the copolymer are provided. According to the copolymerization method, a cyclic olefin and a polar vinyl olefin can be effectively copolymerized using a catalyst system composed of a compound containing a group 13 element and a radical initiator. The resulting copolymer is transparent, and has high adhesion, thermal stability, optical anisotropy and strength, and a low dielectric constant. The optical film including the copolymer can be used as a plastic lens, a polarizer protective film, an adhesive film, and a compensation film, and in a LCD display. | 02-11-2010 |
20100174039 | Catalyst system for polymerizing cyclic olefin having polar functional group, polymerizing method using the catalyst system, olefin polymer produced by the method and optical anisotropic film comprising the olefin polymer - A catalyst system capable of producing a cyclic olefin polymer having a polar functional group and a high molecular weight with a high yield in which a catalyst is not deactivated due to polar functional groups of monomers, and a method of producing polymers using the same are provided. The catalyst system for polymerization of olefin according to the present invention has good thermal and chemical stability, and thus, in the method of preparing polyolefin using the catalyst system, the deactivation of a catalyst due to a polar functional group of the monomer can be prevented, and thus a high yield of the cyclic olefin polymer with a high molecular weight can be obtained when a ratio of the catalyst to the monomer is 1:5000, and the removal of a catalyst residue is not required. | 07-08-2010 |
20110245069 | CATALYST SYSTEM FOR PREPARING CYCLIC OLEFIN ADDITION POLYMER, CYCLIC OLEFIN ADDITION POLYMER PREPARED BY USING THE CATALYST SYSTSEM AND METHOD FOR PREPARING THE SAME - The present invention relates to a catalyst system for preparing a cyclic olefin addition polymer, a method for preparing the catalyst system and a cyclic olefin addition polymer prepared by the method, and more particularly to the method comprising the steps of contacting some content of norbornene-based monomer having a specific polar functional group with a catalyst system comprising a) a Group X transition metal compound; b) a compound comprising a neutral Group XV electron donor ligand having a cone angle of at least 160°; and c) a salt capable of offering an anion that can be weakly coordinated to the transition metal of the a) the Group X transition metal compound. | 10-06-2011 |
Patent application number | Description | Published |
20080219047 | APPARATUS AND METHOD FOR WRITING DATA TO PHASE-CHANGE MEMORY BY USING POWER CALCULATION AND DATA INVERSION - Provided are an apparatus and method for writing data to a phase-change random access memory (PRAM) by using writing power calculation and data inversion functions, and more particularly, an apparatus and method for writing data which can minimize power consumption by calculating the power consumed while input original data or inverted data is written to a PRAM and storing the data consuming less power. A PRAM consumes a significant amount of power in order to store data in a memory cell since a large electric current is required to flow for a long period of time. According to the present invention, since the PRAM consumes different amounts of power when writing data with a value of 0 and data with a value of 1, the power consumed when input original data is stored and the power consumed when the input original data is inverted and stored are compared to each other, the data with a smaller power consumption is stored when the data is written to the PRAM as a word unit, and thus the power consumption of the PRAM can be reduced. | 09-11-2008 |
20080237564 | Phase-Change Memory Device Using Sb-Se Metal Alloy and Method of Fabricating the Same - Provided are a phase-change memory device using a phase-change material having a low melting point and a high crystallization speed, and a method of fabricating the same. The phase-change memory device includes an antimony (Sb)-selenium (Se) chalcogenide Sb | 10-02-2008 |
20100148141 | NON-VOLATILE PROGRAMMABLE DEVICE INCLUDING PHASE CHANGE LAYER AND FABRICATING METHOD THEREOF - Provided is a non-volatile programmable device including a first terminal, a first threshold switching layer connected to part of the first terminal, a phase change layer connected to the first threshold switching layer, a second threshold switching layer connected to the phase change layer, a second terminal connected to the second threshold switching layer, and third and fourth terminals respectively connected to a side portion of the phase change layer and the other side portion opposite to the side portion of the phase change layer. | 06-17-2010 |
20110065246 | EMBEDDED PHASE-CHANGE MEMORY AND METHOD OF FABRICATING THE SAME - An embedded memory required for a high performance, multifunction SOC, and a method of fabricating the same are provided. The memory includes a bipolar transistor, a phase-change memory device and a MOS transistor, adjacent and electrically connected, on a substrate. The bipolar transistor includes a base composed of SiGe disposed on a collector. The phase-change memory device has a phase-change material layer which is changed from an amorphous state to a crystalline state by a current, and a heating layer composed of SiGe that contacts the lower surface of the phase-change material layer. | 03-17-2011 |
20120217465 | NON-VOLATILE PROGRAMMABLE DEVICE INCLUDING PHASE CHANGE LAYER AND FABRICATING METHOD THEREOF - Provided is a non-volatile programmable device including a first terminal, a first threshold switching layer connected to part of the first terminal, a phase change layer connected to the first threshold switching layer, a second threshold switching layer connected to the phase change layer, a second terminal connected to the second threshold switching layer, and third and fourth terminals respectively connected to a side portion of the phase change layer and the other side portion opposite to the side portion of the phase change layer. | 08-30-2012 |