| 摘要 |
A dot pattern is formed either on a surface of a diffuser 35 or of a diffusion sheet 37 facing lamps 33. The dot pattern serves to disperse light at the centre of the lamps 33 and to condense light in a boundary between them. The diffuser 35 may be part of a direct backlight unit for an LCD display that comprises a reflecting plate 31 and a prism sheet 39, and can use either fluorescent tubes or LEDs as a light source. The dot pattern may comprise a main pattern (fig 4, I) at the centre of a lamp that lowers transmissivity and a sub dot pattern (fig 4, II) of relatively smaller size that enhances transmissivity. The dots may be circular or diamond-shaped and are formed by printing using a transparent ink mixed with a reflective white ink. The diffuser 35 reduces the mura or variation in luminance of the backlight.
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