Directive colour filter and naked-eye 3d display apparatus

A directional color filter, comprising:

• a color filter comprising a plurality of filtering units, wherein each of the filtering units comprises at least three filtering subunits for different colors, colors of light transmitted through the filtering subunits for the same color are the same;
• and
• a directional function structure layer arranged on a light emitting surface of the color filter and comprising a plurality of structure units, wherein each of the structure units is arranged corresponding to one of the filtering units, each of the structure units comprises at least three structure subunits, each of the structure subunits is arranged corresponding to one of the filtering subunits, wherein light transmitted through each of the filtering subunits is incident to a corresponding one of the structure subunits,
• wherein each of the structure subunits comprises a plurality of nanometer diffraction gratings;
• nanometer diffraction gratings in the same structure subunit have different periods and different orientation angles, wherein light with the same color transmitted through the same structure subunit has different viewing angles;
• and nanometer diffraction gratings at a same position in structure subunits in the same filtering unit corresponding to filtering subunits for different colors have different periods and different orientation angles, wherein light with different colors for compositing an image with a same viewing angle has the same viewing angle.