Display device

A display device, comprising:

• a display panel;
• a collimation optical element located on a light emission side of the display panel and configured to modulate a first light emitted from the display panel into a collimated second light and emit the collimated second light;
• and
• a light modulation element located on a light emission side of the collimation optical element and configured to adjust an emission angle of the second light from the light modulation element, wherein
• the collimation optical element includes:
• a diffraction grating, configured to convert a first light incident onto the diffraction grating into a parallel light in which light rays are parallel to each other;
• a first covering layer located on a light emission side of the diffraction grating;
• and a second covering layer located on the first covering layer;
• a refractive index of the first covering layer is smaller than a refractive index of the second covering layer, and the first covering layer and the second covering layer are configured to collimate the parallel light emitted from the diffraction grating to obtain the second light;
• each of the diffraction rating, the first covering layer, and the second covering layer is provided on the light emission side of the display panel;
• and
• the first light emitted from the display panel is not perpendicular to a surface of the diffraction grating facing the display panel, but the collimated second light emitted by the collimation optical element is perpendicular to the surface of the diffraction grating facing the display panel.