Light emitting device, display device, and lighting device
A light emitting device includes: a light emitting element; a reflection wall that surrounds the light emitting element; and a diffusion reflection sheet that includes a plurality of particles and permits entrance of emitted light from the light emitting element and reflected light from the reflection wall.
1 . A display device provided with a display panel and a light emitting device that illuminates the display panel, the light emitting device comprising: a light emitting element comprising LEDs (Light Emitting Diodes), the LEDs oriented to be flip chip structures; a light source substrate having a surface on which the light emitting element is disposed; a covering material that covers the LEDs; a reflection wall that surrounds each of the LEDs and comprises a flat portion that is in direct contact with the surface of the light source substrate and a bent portion that surrounds the flat portion, in which the flat portion is parallel with the light source substrate, the reflection wall being a shaped sheet in which the flat portion that contacts the surface of the light source substrate and bent portion are a single resin material that equally reflects light of a first wavelength range more efficiently than light of a second wavelength range, in which the first wavelength range consists of light with shorter wavelengths than light in the second wavelength range, the first wavelength range is blue light and the second wavelength range is visible light; a wavelength conversion member that faces the light source substrate; a diffusion reflection member that is a single resin sheet having particles dispersed therein that cause diffusion and reflection of emitted light from the light source, the diffusion reflection member is in contact with the reflection wall, the particles permit entrance of the emitted light from the light emitting element and reflected light from the reflection wall, and wherein the diffusion reflection member is disposed between the wavelength conversion member and the light source substrate; and an optical member provided between a display panel and the wavelength conversion member; and the display panel comprising: a TFT substrate; a color filter substrate; and a liquid crystal layer between the TFT substrate and color filter substrate, the optical member being between the TFT substrate and the wavelength conversion member.
2 . The display device according to claim 1 , wherein the wavelength conversion member includes quantum dots.
3 . The display device according to claim 2 , wherein the LEDs are side emission-type LEDs.
4 . The display device according to claim 2 , wherein the diffusion reflection member is formed of the single resin sheet with the plurality of particles printed thereon.
5 . The display device according to claim 2 , further comprising a second optical member between the diffusion reflection member and the wavelength conversion member.
6 . The display device according to claim 1 , wherein the light emitting elements are bare flip chip structures that emit light of a blue wavelength range and the LEDs include a shoulder portion that provides a ledge for an n type contact to be at a level different than a p type contact.
7 . The display device according to claim 1 , wherein the wavelength conversion member is excited by light of the blue wavelength range emitted from the light emitting element, and outputs white light to enter the optical member.
8 . The display device according to claim 1 , wherein the covering material includes a resin material and has a substantially hemispherical shape.
9 . The display device according to claim 1 , wherein the optical member includes a brightness enhancement film.
10 . The display device according to claim 1 , further comprising another optical member between the diffusion reflection member and the wavelength conversion member.
11 . The display device according to claim 10 , wherein the another optical member includes a POP (Prism on Prism) or a PPD (Prism on Prism Diffuser).
12 . The display device according to claim 10 , wherein the particles comprise an ink.
13 . The display device according to claim 1 , wherein the LEDs are side emission-type LEDs.
14 . The display device according to claim 1 , wherein the diffusion reflection member is formed of the single resin sheet with the plurality of particles printed thereon.
15 . The display device according to claim 1 , wherein the LEDs are provided in packages each covered with lenses.
16 . The display device of claim 1 , wherein at least some of the plurality of the particles have a hollow structure.
17 . The display device of claim 1 , comprising a driver IC that drives the light emitting element, wherein light emission states of the LEDs are controlled by the driver IC according to segments, to adjust the light emission state of each segment in accordance with pictures to be displayed on the display panel, each segment comprising at least one LED.
18 . The display device of claim 17 , wherein each segment comprises multiple LEDs.
19 . The display device according to claim 1 , wherein the covering material has a refractive index between the refractive index of air and a refractive index of the LEDs.
20 . The display device according to claim 1 , wherein the reflection wall includes a horizontal part and an inclined part.