Abstract:
Disclosed is a light emitting diode (LED) package having an array of light emitting cells coupled in series. The LED package comprises a package body and an LED chip mounted on the package body. The LED chip has an array of light emitting cells coupled in series. Since the LED chip having the array of light emitting cells coupled in series is mounted on the LED package, it can be driven directly using an AC power source.
Abstract:
An LED package is disclosed herein. The disclosed LED package comprises a base having an LED chip mounted thereon, an encapsulation member formed by a light-transmittable resin to encapsulate the LED chip, and a housing formed to expose a top portion of the encapsulation member and to encompass a side surface of the encapsulation member, wherein the encapsulation member is formed by a transfer molding process using a mold to have a predetermined shape. Further, the housing may be light-transmittable.
Abstract:
A light emitting device having oxyorthosilicate luminophores is disclosed. The light emitting device includes a light emitting diode and luminescent substances disposed around the light emitting diode, to adsorb at least a portion of light emitted from the light emitting diode and emitting light having different wavelength from that of the absorbed light. The luminescent substances have Eu2+-doped silicate luminophores in which solid solutions in the form of mixed phases between alkaline earth metal oxyorthosilicates and rare earth metal oxyorthosilicates are used as base lattices for the Eu2+ activation leading to luminescence. The luminescent substances are used as radiation converters to convert a higher-energy primary radiation, for example, ultra violet (UV) radiation or blue light, into a longer-wave visible radiation and are therefore preferably employed in corresponding light-emitting devices.
Abstract:
Disclosed is an improved light-emitting device for an AC power operation. A conventional light emitting device employs an AC light-emitting diode having arrays of light emitting cells connected in reverse parallel. The arrays in the prior art alternately repeat on/off in response to a phase change of an AC power source, resulting in short light emission time during a ½ cycle and the occurrence of a flicker effect. An AC light-emitting device according to the present invention employs a variety of means by which light emission time is prolonged during a ½ cycle in response to a phase change of an AC power source and a flicker effect can be reduced. For example, the means may be switching blocks respectively connected to nodes between the light emitting cells, switching blocks connected to a plurality of arrays, or a delay phosphor. Further, there is provided an AC light-emitting device, wherein a plurality of arrays having the different numbers of light emitting cells are employed to increase light emission time and to reduce a flicker effect.
Abstract:
Disclosed is a light emitting device having a plurality of light emitting cells. The light emitting device comprises a thermally conductive substrate, such as a SiC substrate, having a thermal conductivity higher than that of a sapphire substrate. The plurality of light emitting cells are connected in series on the thermally conductive substrate. Meanwhile, a semi-insulating buffer layer is interposed between the thermally conductive substrate and the light emitting cells. For example, the semi-insulating buffer layer may be formed of AlN or semi-insulating GaN. Since the thermally conductive substrate having a thermal conductivity higher than that of a sapphire substrate is employed, heat-dissipating performance can be enhanced as compared with a conventional sapphire substrate, thereby increasing the maximum light output of a light emitting device that is driven under a high voltage AC power source. In addition, since the semi-insulating buffer layer is employed, it is possible to prevent an increase in a leakage current through the thermally conductive substrate and between the light emitting cells.
Abstract:
Exemplary embodiments of the present invention disclose inorganic luminescent substances with Eu2+-doped silicate luminophores, in which solid solutions in the form of mixed phases between alkaline earth metal oxyorthosilicates and rare earth metal oxyorthosilicates are used as base lattices for the Eu2+ activation leading to the luminescence. These luminophores are described by the general formula (1-x) MII3SiO5.xSE2SiO5:Eu, in which MII preferably represents strontium ion or another alkaline earth metal ion, or another divalent metal ion selected from the group consisting of the magnesium, calcium, barium, copper, zinc, and manganese. These ions may be used in addition to strontium and also as mixtures with one another.
Abstract:
Disclosed is an improved light-emitting device for an AC power operation. A conventional light emitting device employs an AC light-emitting diode having arrays of light emitting cells connected in reverse parallel. The arrays in the prior art alternately repeat on/off in response to a phase change of an AC power source, resulting in short light emission time during a ½ cycle and the occurrence of a flicker effect. An AC light-emitting device according to the present invention employs a variety of means by which light emission time is prolonged during a ½ cycle in response to a phase change of an AC power source and a flicker effect can be reduced. For example, the means may be switching blocks respectively connected to nodes between the light emitting cells, switching blocks connected to a plurality of arrays, or a delay phosphor. Further, there is provided an AC light-emitting device, wherein a plurality of arrays having the different numbers of light emitting cells are employed to increase light emission time and to reduce a flicker effect.
Abstract:
Disclosed is a light emitting device having a plurality of light emitting cells. The light emitting device comprises a thermally conductive substrate, such as a SiC substrate, having a thermal conductivity higher than that of a sapphire substrate. The plurality of light emitting cells are connected in series on the thermally conductive substrate. Meanwhile, a semi-insulating buffer layer is interposed between the thermally conductive substrate and the light emitting cells. For example, the semi-insulating buffer layer may be formed of AlN or semi-insulating GaN. Since the thermally conductive substrate having a thermal conductivity higher than that of a sapphire substrate is employed, heat-dissipating performance can be enhanced as compared with a conventional sapphire substrate, thereby increasing the maximum light output of a light emitting device that is driven under a high voltage AC power source. In addition, since the semi-insulating buffer layer is employed, it is possible to prevent an increase in a leakage current through the thermally conductive substrate and between the light emitting cells.
Abstract:
Disclosed is a light emitting diode (LED) package having multiple molding resins. The LED package includes a pair of lead terminals and a heat sink inserted into a heat sink support ring. At least portions of the pair of lead terminals and the heat sink are embedded in a package main body. The package main body has an opening through which the pair of lead terminals is exposed. An LED die is mounted in the opening and electrically connected to the pair of lead terminals. A first molding resin covers the LED die. A second molding resin with higher hardness than the first molding covers the first molding resin. Therefore, stress to be imposed on the LED die can be reduced and the deformation of the molding resins can be prevented.
Abstract:
Disclosed is a light emitting device having a plurality of light emitting cells and a package having the same mounted thereon. The light emitting device includes a plurality of light emitting cells which are formed on a substrate and each of which has an N-type semiconductor layer and a P-type semiconductor layer located on a portion of the N-type semiconductor layer. The plurality of light emitting cells are bonded to a submount substrate. Accordingly, heat generated from the light emitting cells can be easily dissipated, so that a thermal load on the light emitting device can be reduced. Meanwhile, since the plurality of light emitting cells are electrically connected using connection electrodes or electrode layers formed on the submount substrate, it is possible to provide light emitting cell arrays connected to each other in series. Further, it is possible to provide a light emitting device capable of being directly driven by an AC power source by connecting the serially connected light emitting cell arrays in reverse parallel to each other.