To provide a liquid crystal display device without fear of generation of gaps or mechanical distortion at coupling parts among light guide plate blocks divided due to thermal influence such as thermal expansion or thermal contraction caused by temperature changes and capable of alleviating luminance unevenness.

For an optical liquid crystal display device provided with a primary light source emitting light from an upper direction to a lower direction and a light guide plate outputting light incident from the primary light source frontward as a plane light source, the light guide plate is structured of a plurality of light guide plate blocks of one row and eight columns or two rows and eight columns, fixing tools for positioning in up-and-down and right-and-left directions are provided, and further, the fixing tools are provided with protrusions for fixing intervals between the light guide plates and a liquid crystal panel.