Optical sheet, image source unit, display device, process for producing optical sheet, and method for manufacturing display device

A display device configured to output an image to an observer side, comprising:

• a plasma display panel;
• and
• a layered sheet stacked on an image output side of the plasma display panel directly,
• wherein the layered sheet has a plurality of layers that control light emitted from the plasma display panel to emit the light to the observer side,
• at least one of the plurality of layers is a base material layer,
• one layer disposed on the observer side of the base material layer is an optical functional sheet layer, which comprises:
• prisms being arranged in parallel along the sheet surface of the layered sheet whereby light can be transmitted;
• and light-absorbing parts being arranged in parallel between the prisms whereby light can be absorbed,
• the light-absorbing part contains light-absorbing particles with an average particle of 1 μm or more
• one layer disposed on the plasma display panel side surface of the base material layer is an adhesive layer,
• the layered sheet has a layer that blocks electromagnetic waves and/or a layer that corrects color tone, and
• the prism of the optical functional sheet layer in a cross section of the optical functional layer has a trapezoidal shape whose long lower base is located at the plasma display panel side, and short upper base is located at the observer side.