Holographic display method and apparatus using optical fiber array backlight for portable device

• US 9,756,317 B2
• Filed: 01/20/2015
• Issued: 09/05/2017
• Est. Priority Date: 01/20/2014
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kim, Hyun Eui, Kim, Jin Woong, Moon, Kyung Ae, Park, Min Sik
• Primary Examiner(s): Kakalec, Kimberly N
• Application Number:
  US14/600,806
• Publication Number:
  US 20150205259A1
• Time in Patent Office: 959 Days
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: G02B 27/0025 for optical correction, e.g. distorsion, aberration
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G02B 6/0008 the light being emitted at the end of the fibre
• CPC Class Codes: G02B 6/2706 as bulk elements, i.e. free space arrangements external to a light guide, e.g. polarising beam splitters
• CPC Class Codes: G03H 1/2286 Particular reconstruction light G03H1/24 takes precedence; Beam properties
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 2001/221 Element having optical power, e.g. field lens
• CPC Class Codes: G03H 2001/2236 Details of the viewing window
• CPC Class Codes: G03H 2001/2242 Multiple viewing windows
• CPC Class Codes: G03H 2222/18 RGB trichrome light
• CPC Class Codes: G03H 2222/34 Multiple light sources
• CPC Class Codes: G03H 2223/16 Optical waveguide, e.g. optical fibre, rod
• CPC Class Codes: G03H 2226/05 Means for tracking the observer
• CPC Class Codes: H04N 13/31 using parallax barriers

Abstract

The present invention discloses a holographic display apparatus including a light irradiating unit configured to irradiate light using an optical fiber array backlight, a spatial light modulator (SLM) configured to perform modulating the irradiated light, a lens configured to irradiate hologram images based on the modulated light, a pupil tracking unit configured to acquire location of an observer'"'"'s pupil by pupil tracking, and a hologram generating unit configured to generate parallax hologram images that correspond to the location of pupil.

Claims

1. A holographic display apparatus, comprising:

a light irradiating unit configured to irradiate light using an optical fiber array backlight;

a spatial light modulator (SLM) configured to perform modulating the irradiated light;

a lens configured to irradiate hologram images based on the modulated light;

a pupil tracking unit configured to acquire a location of an observer'"'"'s pupil by pupil tracking; and

a hologram generating unit configured to generate parallax hologram images that correspond to the location of the pupil,

wherein the light irradiating unit comprises a viewing window array provided by arranging a light source array in an arc shape with respect to horizontal and vertical directions.

2. The holographic display apparatus of claim 1, wherein the hologram generating unit changes a location of a viewing window included in the viewing window array by performing off-axis hologram encoding when generating a hologram in order to supplement a spatial gap between viewing windows included in the viewing window array.

3. The holographic display apparatus of claim 1, wherein the light irradiating unit comprises an optical fiber laser and an optical fiber.

4. The holographic display apparatus of claim 3, wherein the light irradiating unit comprises:

an optical fiber coupler configured to diverge the optical fiber laser beam into paths; and

a RGB combiner configured to generate white light using the diverged optical fiber laser beam.

5. The holographic display apparatus of claim 4, wherein the light irradiating unit comprises:

a half wave polarizing plate and a polarizing plate installed between respective optical fibers that are diverged into several parts in order to control a polarization direction of an incident beam and a power of light; and

a light collimator installed at a terminal of the optical fiber in order to irradiate plane waves to the spatial light modulator.

6. The holographic display apparatus of claim 1, further comprising a noise mask configured to filter diffracted high-order terms and twin images.

7. The holographic display apparatus of claim 6, wherein the lens is a field flattener lens, and

wherein a viewing window included in the viewing window array is formed at a focal distance by focusing the modulated light into a focal point of the lens.

8. The holographic display apparatus of claim 1, wherein the pupil tracking unit comprises a stereo camera and an infrared LED.

9. A holographic display method, comprising:

irradiating light using an optical fiber array backlight;

modulating the irradiated light performed by a spatial light modulator (SLM);

irradiating hologram images by passing the modulated light through a lens;

tracking a pupil for acquiring a location of an observer'"'"'s pupil by pupil tracking; and

generating parallax hologram images that correspond to the location of the pupil,

wherein irradiating the light comprises diverging optical fiber laser beam into paths and generating white light through an RGB combiner.

10. The holographic display method of claim 9, wherein generating the hologram images comprises changing a location of a viewing window by performing off-axis hologram encoding when generating a hologram in order to supplement spatial gap between viewing windows.

11. The holographic display method of claim 10, wherein irradiating the light comprises:

controlling a polarization direction of incident beam and power of light by installing a half wave polarizing plate and a polarizing plate between respective optical fibers that are diverged into several parts; and

irradiating a plane wave to the spatial light modulator through a light collimator installed at a terminal of the optical fiber.

12. The holographic display method of claim 9, further comprising filtering diffracted high-order terms and twin images by a noise mask.

13. The holographic display method of claim 9, wherein the lens is a field flattener lens, and

wherein irradiating the hologram comprises forming a viewing window at a focal distance by focusing the modulated light into a focal point of the lens.

14. The holographic display method of claim 9, wherein tracking the pupil comprises acquiring the location of the observer'"'"'s pupil using a stereo camera and an infrared LED.

15. A holographic display method, comprising:

irradiating light using an optical fiber array backlight;

modulating the irradiated light performed by a spatial light modulator (SLM);

irradiating holograms images by passing the modulated light through a lens;

tracking a pupil for acquiring a location of an observer'"'"'s pupil by pupil tracking; and

generating parallax hologram images that correspond to the location of the pupil,

wherein irradiating the light comprises forming a viewing window array provided by arranging a light source array in an arc shape with respect to horizontal and vertical directions.