Back light unit and liquid crystal display using the same

A back light unit comprising:

• a printed circuit board;
• a plurality of LED light sources light emitting devices on a the printed circuit board;
• a resin layer which is laminated on the printed circuit board and buries burying the plurality of LED light sources, wherein the resin layer comprises 10-21% of an oligomer, 30-63% of a monomer, and 1.5-6% of additives light emitting devices;
• a diffusion plate disposed on an upper surface of the resin layer;
• and
• an optical pattern disposed between the diffusion plate and the resin layer,
• wherein the optical pattern comprises a light shielding pattern and a diffusion pattern on the light shielding pattern, the diffusion pattern comprising a material different from that of the light shielding pattern and having a pattern shape different from that of the light shielding pattern, such that the optical pattern controls the extent of light that is diffused and light that is shielded;
• first pattern and a second pattern,
• wherein the light shielding second pattern has a pattern shape having a recess and a protrusion in a light emission direction different from a pattern shape of the first pattern,
• wherein the diffusion pattern shields, reflects, and diffuses light;
• wherein the light shielding pattern shields and reflects light,
• wherein the diffusion pattern is in contact with a bottom surface of the diffusion plate,
• wherein the light shielding first pattern comprises:
• a first part being in direct physical contact with a part of the diffusion the second pattern and vertically overlapped with the part of the diffusion second pattern, and a second part not vertically overlapped with the LED light source;
• and second pattern,
• wherein the first part is disposed in a light exit direction of the light emitting device,
• wherein the first pattern and the second pattern are formed so that a pattern density is lowered in a light emission direction, and
• wherein a portion of the optical pattern is disposed to vertically overlap the light emitting device
• wherein the diffusion pattern is not overlapped with the LED light source and comprises a first diffusion pattern entirely vertically overlapped with the light shielding pattern, and a second diffusion pattern partially vertically overlapped with the light shielding pattern.