Recently, liquid crystal display devices have been widely employed as display devices for smartphones, personal digital assistants (PADs), tablet computers, car navigation systems and the like. In general, a liquid crystal display device comprises a liquid crystal display panel and a planar lighting device (backlight device) overlaid on a rear surface of the liquid crystal display panel to illuminate the liquid crystal display panel. A conventional backlight device comprises a reflection layer, a light guide, an optical sheet, a light source such as an LED, and a rectangular mold frame. The reflection layer, the light guide, and the optical sheet are overlaid and stacked on each other, and disposed inside the mold frame.
In addition, a liquid crystal display device having a force sensing function of sensing the pressing force input on its display surface and executing an arbitrary operation based on the force sensing has been proposed. A variation in distance between two electrodes provided in the liquid crystal display device is read as an electrostatic capacity variation, which is considered as capacitance-type input sensing for sensing the pressing force. For this reason, that a decent amount of stroke between the two electrodes is linearly varied to the pressing force in the thickness direction (external force in the thickness direction) needs to be secured.