A light-guide module includes a light-guide strip having opposite first and second ends, a light-entry surface disposed at the first end, a light-exit surface extending between the first and second ends, and first and second working surfaces disposed parallel to each other and extending between the first and second ends. One of the first and second working surfaces defines a light-scatter zone and includes a plurality of micro-scatter structures that are disposed within the light-scatter zone and that configure the light-scatter zone with a light-scattering ability that varies from the first end to the second end. The light-guide module also includes a reflecting element disposed to reflect light that exits from the light-guide strip via the first and second working surfaces back into the light-guide strip via the first and second working surfaces, respectively.