Abstract: A plane light source unit for backlighting and a method for manufacturing holographic light-guides used for the same is disclosed. The holographic light-guide has a first holographic layer on the bottom surface. The first holographic layer has patterns formed with a plurality of holograms, the area density of the pattern being low toward the tubular light source and increasing with an increase in distance from the tubular light source, thereby uniformly illuminating the LCD panel. The holographic light-guide also has a second holographic layer on the top surface, the second holographic layer adjusting scattering pattern of the beam emerged from the light-guide plate.