Abstract: An organic light emitting display device includes a substrate in which a pixel is defined, the pixel including a white sub-pixel which includes an emission area and a non-emission area; a first light emitting diode located in the white sub-pixel; and a light extraction layer located on an outer surface of the substrate corresponding to a transmission direction of a light emitted from the first light emitting diode, wherein the light extraction layer includes a first lens corresponding to the emission area and a second lens corresponding to the non-emission area, wherein a height of the first lens is greater than a height of the second lens.

Abstract: A backlight unit includes a diffusion plate, wherein the diffusion plate includes a first region along edges of the diffusion plate, and a second region surrounded by the first region, and wherein a thickness of the first region decreases toward an outer side direction of the diffusion plate.

Abstract: A backlight unit includes a diffusion plate, wherein the diffusion plate includes a first region along edges of the diffusion plate, and a second region surrounded by the first region, and wherein a thickness of the first region decreases toward an outer side direction of the diffusion plate.

Abstract: A light emitting diode package includes: a light emitting diode (LED); and an LED lens over the LED, the LED lens having a symmetrical shape with respect to a central axis, wherein the LED lens includes a lower surface having first and second lower surfaces, an upper surface and a side surface connecting the lower surface and the upper surface, wherein the light through the first lower surface is totally reflected on the upper surface and is emitted though the side surface, wherein the first lower surface includes a first curved surface extending from the central axis and a second curved surface extending from a first end portion of the first curved surface, and wherein the second lower surface is flat and extends from a second end portion of the second curved surface.

Abstract: A light emitting diode package includes: a light emitting diode (LED); and an LED lens over the LED, the LED lens having a symmetrical shape with respect to a central axis, wherein the LED lens includes a lower surface having first and second lower surfaces, an upper surface and a side surface connecting the lower surface and the upper surface, wherein the light through the first lower surface is totally reflected on the upper surface and is emitted though the side surface, wherein the first lower surface includes a first curved surface extending from the central axis and a second curved surface extending from a first end portion of the first curved surface, and wherein the second lower surface is flat and extends from a second end portion of the second curved surface.

Abstract: A heat exchanger for a heat exchange operation such as sensible heat exchange, evaporation and condensation, and more particularly, a serpentine-type serviceable heat exchanger where a heat exchanger coil which guides a heat transfer medium for a heat exchange is formed in a serpentine shape, and a method for manufacturing the same. The serpentine-type serviceable heat exchanger includes a heat exchanger coil having a plurality of linear coils disposed in parallel, and a connection coil disposed between the two neighboring linear coils and fittedly-coupled to the linear coils such that a serpentine-type inner passage is formed as the linear coils are connected to each other by the connection coil; and a frame having an edge forming portion which forms an edge such that the heat exchanger coil is installed therein, and a supporting portion which supports the heat exchanger coil installed in an edge formed by the edge forming portion.

Abstract: Disclosed is a freezing protection system of a heat exchanger capable of preventing freezing of a heat exchanger. The system includes a discharge valve for opening and closing a discharge pipe of a fluid inside a heat exchanger; a freezing factor detection unit for detecting a freezing factor such that the discharge pipe is open, under an automatic control of the discharge valve, upon detection of the freezing factor when the heat exchanger is in a standstill state; and a discharge completion detection unit for detecting whether the fluid inside the heat exchanger has been completely discharge or not, such that the open discharge valve is closed under an automatic control of the discharge valve after the fluid inside the heat exchanger has been completely discharged.