A contrast improving sheet includes a first optical functional element and
a second optical functional element on the viewing side thereof. The
first optical functional element has a plurality of protrusions, each
having a pair of opposite total-reflection facets for totally reflecting
image light rays substantially perpendicularly incident on the entrance
surface and a flat facet extending between the front edges, on the side
of the exit surface, of the pair of opposite total-reflection facets.
Light absorbing layers are formed between the adjacent protrusions. The
second optical functional element has a light path correcting layer for
correcting light paths followed by the image light rays totally reflected
by the total-reflection facets such that the image light rays are emitted
through the exit surface substantially perpendicularly to the exit
surface. The light path correcting layer has a plurality of alternately
inclined planes inclined in opposite directions.