and connected between the light emitting face 24 and the bottom face 23 the fluorescence layer 1 is formed on the light emitting face 24 the fluorescence layer 1 comprises multiple micro structures 12 arranged in parallel as shown in fig2 an inner package of the micro structure has multiple quantum dots and the micro structure 12 has a micro structural light incident face formed on the light emitting face 24 a middle part of the micro structure 12 is thicker than two edge parts of the micro structure 12 along a direction being perpendicular to the micro structural light incident face it can understand that u201c the thicker middle part and two thinner edge parts u201d means that along the direction being perpendicular to the micro structural light incident face a distance between a top of the middle part of the micro structure and the micro structural light incident face is longer than a distance between a top of the edge part and the micro structural light incident face this structure can condense lights to increase a brightness of the light guide plate as shown in fig2 the quantum dots 11 in the inner package of the micro structure 12 includes large quantum dots 112 and small quantum dots 111 an emission spectrum of the quantum dot is controlled by changing sizes of the quantum dot 11 the size of the quantum dot 11 is changed to allow that the emission spectrum.