Module controlling viewing window, device for hologram display and method for displaying hologram

1. A viewing window control module applied to a hologram display device, the viewing window control module comprising:

a viewing window forming unit having a first reflective optical system that receives an incident light and forms a viewing window in a user's viewing region; and

a viewing angle expanding unit having a second reflective optical system that is arranged in one direction on and integrated with the viewing window forming unit and expands a viewing angle of the viewing window,

wherein the viewing angle expanding unit has a plurality of second reflective optical systems that are sequentially arranged at a predetermined pitch in the one direction on a light receiving surface of the viewing window forming unit,

wherein the second reflective optical system has an arrangement pitch based on a pixel pitch of a spatial light modulator from which the incident light is output.

2. The viewing window control module of claim 1 , wherein the viewing angle expanding unit is machined and formed on the viewing window forming unit.

3. The viewing window control module of claim 1 , wherein the first reflective optical system is configured in a concave mirror shape.

4. The viewing window control module of claim 3 , wherein a distance of the viewing window is determined by a radius of curvature of the first reflective optical system.

5. The viewing window control module of claim 1 , wherein the second reflective optical system is configured as a micro-concave mirror.

6. The viewing window control module of claim 5 , wherein the viewing angle is determined by a diameter of the micro-concave mirror and a radius of curvature of the micro-concave mirror.

7. The viewing window control module of claim 1 , wherein the second reflective optical system is configured as a micro-convex mirror.

8. A hologram display device comprising:

a spatial light modulator configured to include a plurality of pixels and to modulate an input light into a diffracted light;

a lens unit configured to emit the diffracted light; and

a viewing window control module configured to provide the emitted diffracted light to a user's viewing region,

wherein the viewing window control module comprises:

a viewing window forming unit having a first reflective optical system that receives the emitted diffracted light and forms a viewing window in the viewing region; and

a viewing angle expanding unit having a second reflective optical system that is arranged in one direction on and integrated with the viewing window forming unit and expands a viewing angle of the viewing window,

wherein the viewing angle expanding unit has a plurality of second reflective optical systems that are sequentially arranged at a predetermined pitch in the one direction on a light receiving surface of the viewing window forming unit,

wherein the second reflective optical system has an arrangement pitch based on a pixel pitch of the spatial light modulator.

9. The hologram display device of claim 8 , wherein the viewing angle expanding unit is machined and formed on the viewing window forming unit.

10. The hologram display device of claim 8 , wherein the first reflective optical system is configured in a concave mirror shape.

11. The hologram display device of claim 10 , wherein a distance of the viewing window is determined by a radius of curvature of the first reflective optical system.

12. The hologram display device of claim 8 , wherein the second reflective optical system is configured as a micro-concave mirror.

13. The hologram display device of claim 12 , wherein the viewing angle is determined by a diameter of the micro-concave mirror and a radius of curvature of the micro-concave mirror.

14. The hologram display device of claim 8 , wherein the second reflective optical system is configured as a micro-convex mirror.

15. The hologram display device of claim 8 , wherein the emitted diffracted light is configured to be irradiated on-axis to the viewing window control module when a beam splitter is used, and the emitted diffracted light is configured to be irradiated off-axis to the viewing window control module when no beam splitter is used.

16. A method for displaying hologram comprising:

modulating, by a spatial light modulator including a plurality of pixels, an input light into a diffracted light;

emitting, by a lens unit, the diffracted light; and

providing, by a viewing window control module, the emitted diffracted light to a user's viewing region,

wherein the providing to the viewing region comprises:

receiving the emitted diffracted light, by a viewing window forming unit having a first reflective optical system, and forming a viewing window on the viewing region; and

expanding, by a viewing angle expanding unit having a second reflective optical system arranged in one direction on and integrated with the viewing window forming unit, a viewing angle of the viewing window,

wherein the viewing angle expanding unit has a plurality of second reflective optical systems that are sequentially arranged at a predetermined pitch in the one direction on a light receiving surface of the viewing window forming unit,

wherein the second reflective optical system has an arrangement pitch based on a pixel pitch of the spatial light modulator.