Floating image display device and electronic device including the same

A floating image display device comprising:

• an image forming device configured to form a source image;
• a waveguide configured to guide a light of the source image input into the waveguide at one location to be output at another location;
• a holographic optical device provided on a proceeding path of the light output from the waveguide, the holographic optical device including a hologram pattern configured to diffract the light having a first incident angle region by a target diffraction angle;
• and
• a floating element including a plurality of corner reflectors, the floating element configured to form a floating image of the source image by forming an image of the light output from the holographic optical device at a first location away from the floating element in mid-air,
• wherein the hologram pattern is a polarization dependent hologram pattern configured to output a primary light diffracted by the target diffraction angle and a non-diffracted zero-order light in different polarization states.

An electronic device comprising:

• a floating image display device comprising:
• an image forming device configured to form a source image;
• a waveguide configured to guide a light of the source image input into the waveguide at a first location to be output at a second *location;
• a holographic optical device provided on a proceeding path of the light output from the waveguide, the holographic optical device including a hologram pattern configured to diffract the light having a first incident angle region by a target diffraction angle;
• and
• a floating element including a plurality of corner reflectors, the floating element configured to form a floating image of the source image by forming an image of the light output from the holographic optical device at a first location away from the floating element in mid-air,
• wherein the holographic optical device comprises a plurality of hologram pattern layers configured to selectively act according to an incident angle of the light, and
• wherein a first hologram pattern layer, among plurality of hologram pattern layers, comprises a plurality of types of angular selective hologram patterns, each having different reaction angle regions.