Abstract: A lighting apparatus includes a light emitting diode, in which the light emitting diode includes an n-type nitride semiconductor layer, an active layer located on the n-type nitride semiconductor layer, and a p-type nitride semiconductor layer located on the active layer. The light emitting diode emits light that varies from yellow light to white light depending on a driving current.

Abstract: Provided are photon counting apparatuses and methods, and radiographic imaging apparatuses configured to receive charge signals corresponding to incident radiation photons, and to count the incident radiation photons by using a plurality of counting bits, such that the counting changes only one counting bit from among the plurality of counting bits when the count value is increased by one. By using the photon counting methods, a data-change frequency of photon counting data corresponding to radiation photons is minimized while counting the radiation photons based on charge signals corresponding to input radiation photons.

Abstract: An apparatus for generating an image may include a plurality of scintillator layers configured to convert an incident beam into an optical signal; a plurality of micro cells configured to turn on or off depending on whether or not the micro cells detect the optical signal; a reaction depth determining unit configured to detect a decay pattern of the optical signal, on the basis of on/off signals of the micro cells, and configured to determine a type of the scintillator layers with which the incident beam has reacted; and/or a reading unit configured to decide an occurrence location of the incident beam and then generates a photographed image.

Abstract: A driver circuit outputs a result of classifying and counting photons based on one or more energy levels to a column line. The driver circuit includes a multiplexer for receiving the result from a counter, a driving inverter for receiving a signal from the multiplexer and a power supply, and a switch connected between the power supply and an input terminal of the driving inverter.

Abstract: Provided are photon counting apparatuses and methods, and radiographic imaging apparatuses configured to receive charge signals corresponding to incident radiation photons, and to count the incident radiation photons by using a plurality of counting bits, such that the counting changes only one counting bit from among the plurality of counting bits when the count value is increased by one. By using the photon counting methods, a data-change frequency of photon counting data corresponding to radiation photons is minimized while counting the radiation photons based on charge signals corresponding to input radiation photons.

Abstract: A photomultiplier detector cell for tomography includes a detector unit and a readOUT unit. The detector unit is configured to generate a digitized detect signal in response to receives light having a certain range of wavelength. The readOUT unit is configured to generate an output signal corresponding to the detect signal generated by the detector unit and to transmit the output signal to an external circuit. The readOUT unit is configured to transmit the output signal to the external circuit right after the detect signal is received.

Abstract: A silicon photomultiplier detector cell may include a photodiode region and a readout circuit region formed on a same substrate. The photodiode region may include a first semiconductor layer exposed on a surface of the silicon photomultiplier detector cell and doped with first type impurities; a second semiconductor layer doped with second type impurities; and/or a first epitaxial layer between the first semiconductor layer and the second semiconductor layer. The first epitaxial layer may contact the first semiconductor layer and the second semiconductor layer. The first epitaxial layer may be doped with the first type impurities at a concentration lower than a concentration of the first type impurities of the first semiconductor layer.

Abstract: A method of calibrating a first threshold voltage that is a reference of X-ray detection for each unit cell of a plurality of unit cells of an X-ray detector may comprise detecting an X-ray by using a plurality of second threshold voltages for each of a plurality of X-rays having spectra at different energy levels; determining a correspondence relationship between energies having a maximum intensity in the spectra of X-rays and third threshold voltages at which a maximum number of photons having a same energy intensity are detected; and/or calibrating the first threshold voltage based on the determined correspondence relationship.

Abstract: A silicon photomultiplier detector cell may include a photodiode region and a readout circuit region formed on a same substrate. The photodiode region may include a first semiconductor layer exposed on a surface of the silicon photomultiplier detector cell and doped with first type impurities; a second semiconductor layer doped with second type impurities; and/or a first epitaxial layer between the first semiconductor layer and the second semiconductor layer. The first epitaxial layer may contact the first semiconductor layer and the second semiconductor layer. The first epitaxial layer may be doped with the first type impurities at a concentration lower than a concentration of the first type impurities of the first semiconductor layer.

Abstract: An apparatus for generating an image may include a plurality of scintillator layers configured to convert an incident beam into an optical signal; a plurality of micro cells configured to turn on or off depending on whether or not the micro cells detect the optical signal; a reaction depth determining unit configured to detect a decay pattern of the optical signal, on the basis of on/off signals of the micro cells, and configured to determine a type of the scintillator layers with which the incident beam has reacted; and/or a reading unit configured to decide an occurrence location of the incident beam and then generates a photographed image.

Abstract: A method of calibrating a first threshold voltage that is a reference of X-ray detection for each unit cell of a plurality of unit cells of an X-ray detector may comprise detecting an X-ray by using a plurality of second threshold voltages for each of a plurality of X-rays having spectra at different energy levels; determining a correspondence relationship between energies having a maximum intensity in the spectra of X-rays and third threshold voltages at which a maximum number of photons having a same energy intensity are detected; and/or calibrating the first threshold voltage based on the determined correspondence relationship.

Abstract: A driver circuit outputs a result of classifying and counting photons based on one or more energy levels to a column line. The driver circuit includes a multiplexer for receiving the result from a counter, a driving inverter for receiving a signal from the multiplexer and a power supply, and a switch connected between the power supply and an input terminal of the driving inverter.

Abstract: According to example embodiments, a photomultiplier detector cell for tomography includes a detector unit and a readOUT unit. The detector unit is configured to generate a digitized detect signal in response to receives light having a certain range of wavelength. The readOUT unit is configured to generate an output signal corresponding to the detect signal generated by the detector unit and to transmit the output signal to an external circuit. The readOUT unit is configured to transmit the output signal to the external circuit right after the detect signal is received.

Abstract: A multilayer metal structure is provided that includes an inner layer of metal materials which are not titanium and outer layers on both sides of the inner layer which are formed by rolling titanium powders. A method for manufacturing the multilayer metal structure is provided that includes preparing titanium powders and metal materials which are not titanium, feeding the titanium powders and the metal materials to a vertical type rolling mill, simultaneously rolling the titanium powders and the metal materials by the rolling mill and forming the multilayer metal structure consisting of an inner layer and outer layers on both sides of the inner layer, and post-forming the multilayer metal structure to increase a packing density.