Diffusing of direct backlight for a display panel

A light guide for receiving and spreading light from a plurality of background illumination sources, comprising:

• a planar light conducting body comprising two opposite surfaces that are an input surface for receiving backlight illumination and an output surface for emitting received backlight illumination;
• the planar light conducting body comprising:
• a plurality of in-coupling structures, each aligned with one of the backlight illumination sources and configured to receive backlight illumination through the input surface and to laterally spread most of the received backlight within the planar light conducting body;
• an out-coupling structure configured to direct most of the laterally spread backlight through the output surface for the emitting of the received backlight illumination;
• the in-coupling structure comprising at least one intruding or protruding form on at least one of the input surface and the output surface;
• and
• the out-coupling structure comprising at least one intruding or protruding form on at least one of the input surface and the output surface;
• wherein the in-coupling structure comprises an in-coupling grating that comprises a form on the input surface configured to focus the received backlight illumination towards the output surface;
• and
• wherein the in-coupling structure is configured to laterally spread by reflecting with a spreading reflector the focused backlight within the planar light conducting body.