As for the dual emission display device, since light is emitted to the
opposite directions from a light emitting element, the both electrodes
provided opposite to the light emitting element are
transparent/translucent. Accordingly, difficulty in black display is
created, and thus, the contrast would be reduced. That results from that
the back of the display device can be seen through in black display, that
is in the OFF state, since the both electrodes have transparency.
Addressing the difficulty in black display with respect to an electronic
device and the like including a dual emission display device achieving
reduction in the thickness and light weighting, pure black display is
performed by providing the dual emission display device part with a
polarizing plate or a circularly polarizing plate. Further, the contrast
can be improved.