One-way homogeneous beam expanding screen and three-dimensional display device

A three-dimensional display device comprising:

• a rotary table rotating around a central axis of the rotary table, wherein the central axis extends in a first direction;
• at least one light pole fixed on the rotary table, wherein the at least one light pole comprises a plurality of projection units, wherein each projection unit of the plurality of projection units is arranged to emit light in at least two directions in a plane perpendicular to the first direction to form at least two viewpoints;
• a plurality of screens for unidirectional beam homogenizing and expanding;
• and further comprising a curved mirror, wherein the curved mirror is positioned between the at least one light pole and the plurality of the screens for unidirectional beam homogenizing and expanding wherein the plurality of screens are arranged to expand, along the first direction, beams of light with different angles of emergence emitted by the plurality of projection units, with propagation direction along the second direction, wherein each screen of the plurality of screens comprises a lenticular grating and a plurality of linear Fresnel lenses, wherein each linear Fresnel lens of the plurality of linear Fresnel lenses is positioned between at least one projection unit of the plurality of the projection units and the lenticular grating, wherein at least one linear Fresnel lens of the plurality of linear Fresnel lenses comprises a plurality of tooth-shaped structures extending along the second direction, and the at least one linear Fresnel lens is arranged to deflect the beams of light emitted by the at least one projection unit to cause the deflected beams of light to enter into the lenticular grating, wherein one or more grid lines of the lenticular grating extend along the second direction, and the one or more grid lines of the lenticular grating is arranged to expand the beams of light from the at least one linear Fresnel lens along the first direction, wherein at least two linear Fresnel lenses of the plurality of linear Fresnel lenses are arranged along the first direction, and wherein the plurality of screens for unidirectional beam homogenizing and expanding are positioned on emergent optical paths of the plurality of projection units.

A three-dimensional display device comprising:

• a rotary table rotating around a central axis of the rotary table, wherein the central axis extends in a first direction;
• at least one light pole fixed on the rotary table, wherein the at least one light pole comprises a plurality of projection units, wherein each projection unit of the plurality of projection units is arranged to emit light in at least two directions in a plane perpendicular to the first direction to form at least two viewpoints;
• and a plurality of screens for unidirectional beam homogenizing and expanding, wherein the plurality of screens are arranged to expand, along the first direction, beams of light with different angles of emergence emitted by the plurality of projection units, with propagation direction along the second direction, wherein each screen of the plurality of screens comprises a lenticular grating and a plurality of linear Fresnel lenses, wherein each linear Fresnel lens of the plurality of linear Fresnel lenses is positioned between at least one projection unit of the plurality of the projection units and the lenticular grating, wherein at least one linear Fresnel lens of the plurality of linear Fresnel lenses comprises a plurality of tooth-shaped structures extending along the second direction, and the at least one linear Fresnel lens is arranged to deflect the beams of light emitted by the at least one projection unit to cause the deflected beams of light to enter into the lenticular grating, wherein one or more grid lines of the lenticular grating extend along the second direction, and the one or more grid lines of the lenticular grating is arranged to expand the beams of light from the at least one linear Fresnel lens along the first direction, wherein at least two linear Fresnel lenses of the plurality of linear Fresnel lenses are arranged along the first direction, wherein the plurality of screens for unidirectional beam homogenizing and expanding are positioned on emergent optical paths of the plurality of projection units, wherein the at least one projection unit is arranged at a focal point of the at least one linear Fresnel lens of at least one screen of the plurality of screens.