Display device, display method, and color separation device

A display device comprising:

• a display panel including a plurality of pixels, wherein pixels among the plurality of pixels associated with different colors are arranged in a first direction and pixels among the plurality of pixels associated with a same color are arranged in a second direction orthogonal to the first direction;
• a color separation device facing the pixels, including a main surface with a convex/concave pattern, and configured to:
• separate an incident light into a plurality of separated lights, and
• output the plurality of separated lights to the plurality of pixels;
• and
• an illumination device including a plurality of light sources and configured to emit the incident light to the color separation device, wherein
• respective ones of the plurality of light sources have a first optional angle spread in the first direction and a second optional angle spread in the second direction,
• the second optional angle spread is wider than the first optional angle spread,
• the plurality of pixels includes a first pixel, a second pixel, a third pixel, a fourth pixel, and a fifth pixel,
• the color separation device includes a first element, a second element, and a third element,
• the first pixel is arranged between the fourth pixel and the second pixel in the first direction,
• the third pixel is arranged between the second pixel and the fifth pixel in the first direction,
• the first element is arranged opposite to the first pixel in a thickness direction, and is configured to diffract light of a first color wavelength to the first pixel, light of a second color wavelength to the second pixel, and light of a third color wavelength to the fourth pixel,
• the second element is arranged opposite to the second pixel in the thickness direction, and is configured to diffract the light of the first color wavelength to the first pixel, the light of the second color wavelength to the second pixel, and the light of the third color wavelength to the third pixel, and
• the third element is arranged opposite to the third pixel in the thickness direction, and is configured to diffract the light of the first color wavelength to the fifth pixel, the light of the second color wavelength to the second pixel, and the light of the third color wavelength to the third pixel.