Optics of wearable display to increase eye-box
A see-through image display system having an Exit-Pupil-Expander (EPE) to enlarge the eyebox of display is disclosed. The EPE uses a hologram functioning as a micro-lens-array as well as collimation lens.
1. A see-through display system comprising:
a light source for emitting a multi-color light beam toward a laser beam scanner (LSB), wherein the LSB scans the multi-color light beam as a plurality of scanned beams toward a diverging hologram plate;
the diverging hologram plate diverges the scanned beams into divergent beams with a predesignated divergent angle for projecting toward a combiner plate, the combiner plate reflecting the divergent beams to create a virtual image and combining with an external image to create a combined image in front of an eye-pupil with a predefined size of an eye-box corresponding to the divergent angle of the diverging beams;
wherein the divergent hologram plate further comprises a light shield with many holes with a size of several microns to diverge the scanned beams by Fraunhofer diffraction.
2. The see-through display system of claim 1 , wherein:
the combiner plate comprises another hologram plate having hologram elements creating the virtual image and combining with the external image to create the combined image in front of the eye-pupil.
3. The see-through display system of claim 1 , wherein:
the combiner plate further comprises a Fresnel mirror for creating the virtual image and combining with the external image to create the combined image in front of the eye-pupil.
4. The display system of claim 1 , wherein:
the combiner plate further comprises a diffractive optical element (DOE) for creating the virtual image and combining with the external image to create the combined image in front of the eye-pupil.
5. The display system of claim 1 , wherein:
the light source further includes a laser light source selected from a group consisting of a laser, light emitting diode (LED) and organic light emitting diode (OLED).