Display device
According to one embodiment, a display device includes an optical element including a transmission axis which transmits first linearly polarized light and reflecting second linearly polarized light which crosses the transmission axis, a display unit which emits display light of the second linearly polarized light towards the optical element, a retroreflector including a retroreflective unit which retroreflects reflection light reflected by the optical element, and a non-retroreflective unit, a modulating element including a modulating unit disposed in a position which overlaps the retroreflective unit, and a non-modulating unit disposed in a position which overlaps the non-retroreflective unit.
1. A display device comprising:
an optical element comprising a transmission axis which transmits first linearly polarized light and reflecting second linearly polarized light which crosses the transmission axis,
a display unit which emits display light of the second linearly polarized light towards the optical element;
a retroreflective element comprising a retroreflective unit which retroreflects reflection light reflected by the optical element, and a non-retroreflective unit which does not retroreflect reflection light reflected by the optical element;
a retarder element comprising a first region disposed in a position which overlaps the retroreflective unit, and a second region disposed in a position which overlaps the non-retroreflective unit, wherein
the retarder element comprises a retardation film,
the second region is an opening through the retardation film of the retarder element.
2. The device of claim 1 , wherein
the retroreflective element comprises a flat surface which opposes the retarder element,
the retroreflective unit and the non-retroreflective unit are located on an opposite side to the flat surface, and
the retarder element is fixed to the flat surface.
3. The device of claim 1 , wherein
the retroreflective element comprises a plurality of retroreflectors, and
the retroreflectors each comprises three reflective surfaces orthogonal to each other.
4. The device of claim 1 , wherein
the second region is hexagonal in plan view.
5. The device of claim 1 , wherein
the first region imparts a phase difference of a quarter wave to transmitted light.
6. The device of claim 5 , wherein
the opening is a hexagon.
7. The device of claim 1 , wherein
the display unit comprises a first substrate, a second substrate which opposes the first substrate, and a liquid crystal layer held between the first substrate and the second substrate.
8. The device of claim 1 , wherein
the retroreflective element comprises a flat surface located on an opposite side to the retroreflective unit and the non-retroreflective unit, and
the retroreflective unit and the non-retroreflective unit are located between the flat surface and the retarder element.
9. The device of claim 8 , wherein
the retarder element is spaced from the retroreflective unit and the non-retroreflective unit.
10. The device of claim 1 , wherein
a phase difference in the second region of the film is substantially zero.
11. The device of claim 10 , wherein
the second region is a hexagon.