OPTICALLY ADDRESSABLE SPATIAL LIGHT MODULATOR DIVIDED INTO PLURALITY OF SEGMENTS, AND HOLOGRAPHIC THREE-DIMENSIONAL IMAGE DISPLAY APPARATUS AND METHOD USING THE LIGHT MODULATOR

• US 20140104664A1
• Filed: 04/08/2013
• Published: 04/17/2014
• Est. Priority Date: 10/16/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Cambridge Enterprise Limited (University of Cambridge)
• Original Assignee: Samsung Electronics Co. Ltd., Cambridge Enterprise Limited (University of Cambridge)
• Inventors: LEE, Hong-seok, CHU, Daping, SONG, Hoon, COLLINGS, Neil, CROSSLAND, William Alden, CHEN, Jhen Si
• Granted Patent: US 9,354,604 B2
• Time in Patent Office: Days
• US Class Current: 359/9
• CPC Class Codes: G02F 1/00 Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
• CPC Class Codes: G02F 1/135 Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied G02F1/133348 takes precedence
• CPC Class Codes: G03H 1/0808 Methods of numerical synthesis, e.g. coherent ray tracing [CRT], diffraction specific
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 2210/30 3D object
• CPC Class Codes: G03H 2222/36 Scanning light beam
• CPC Class Codes: G03H 2225/25 Optically addressed SLM [OA-SLM]
• CPC Class Codes: G03H 2225/32 Phase only
• CPC Class Codes: G03H 2240/41 Binary

Abstract

Provided are an optically addressable spatial light modulator (OASLM) divided into a plurality of segments, and an apparatus and method for displaying a holographic three-dimensional (3D) image using the OASLM. The holographic 3D image display apparatus includes a first light source which emits a write beam, an electric addressable spatial light modulator (EASLM) which modulates the write beam emitted from the first light source according to hologram information regarding a 3D image, a second light source which emits a read beam, an OASLM which receives the write beam modulated by the EASLM and modulates the read beam emitted from the second light source according to hologram information included in the modulated write beam, a scanning optical unit which projects the write beam modulated by the EASLM onto the OASLM, and a Fourier lens which focuses the read beam modulated by the OASLM onto a predetermined space to form the 3D image.

Claims

1. An optically addressable spatial light modulator (OASLM) comprising:

a plurality of divided light modulation segments arranged in a two-dimensional (2D) array;

a plurality of gaps disposed between the plurality of segments; and

a plurality of independent transparent electrodes and a plurality of independent interconnections, wherein one of the plurality of independent transparent electrodes and one of the plurality of independent interconnections is connected to each of the plurality of segments, such that each of the plurality of segments can be turned on/off independently of any other of the plurality of segments.

2. The OASLM of claim 1, further comprising:

a transparent front substrate and a transparent rear substrate;

wherein the plurality of transparent electrodes comprise a plurality of first transparent electrodes disposed on a surface of the front substrate and a plurality of second transparent electrodes disposed on a surface of the rear substrate; and

a photosensitive layer disposed on the first transparent electrodes and a liquid crystal layer disposed on the second transparent electrodes.

3. The OASLM of claim 2, wherein the first transparent electrodes, the second transparent electrodes, the photosensitive layer, and the liquid crystal layer are patterned, thus forming the plurality of segments.

4. The OASLM of claim 3, wherein the plurality of interconnections comprise a plurality of first interconnections which are disposed on the front substrate and are electrically connected to the first transparent electrodes corresponding thereto, and a plurality of second interconnections which are disposed on the rear substrate and are electrically connected to the second transparent electrodes corresponding thereto.

5. The OASLM of claim 4, wherein the plurality of first interconnections and the plurality of second interconnections are disposed in the gaps between the plurality of segments.

6. The OASLM of claim 5, wherein the OASLM further comprises a first half portion and a second half portion disposed opposite the first half portion with respect to a center of the OASLM;

the plurality of first interconnections comprises a plurality of first interconnections disposed in the first half portion and a plurality of first interconnections disposed in the second half portion, and the plurality of second interconnections comprises a plurality of second interconnections disposed in the first half portion and a plurality of second interconnections disposed in the second half portion; and

wherein the plurality of first interconnections disposed in the first half portion and the plurality of second interconnections disposed in the first half portion are connected to a plurality of first transparent electrodes and a plurality of second transparent electrodes disposed in the first half portion, and the plurality of first interconnections disposed in the second half portion and the plurality of second interconnections disposed in the second half portion are connected to a plurality of first transparent electrodes and a plurality of second transparent electrodes disposed in the second half portion.

7. The OASLM of claim 3, wherein the plurality of interconnections comprise:

a plurality of first interconnections which are disposed along an outer surface of the front substrate, which face a region in which the plurality of first transparent electrodes are disposed, and which are electrically connected to the plurality of first transparent electrodes corresponding thereto; and

a plurality of second interconnections which are disposed along an outer surface of the rear substrate, which face a region in which the plurality of second transparent electrodes, and which are electrically connected to the plurality of second transparent electrodes corresponding thereto.

8. The OASLM of claim 7, further comprising:

a first via hole passing through the front substrate, wherein the plurality of first interconnections are electrically connected with the plurality of first transparent electrodes corresponding thereto via the first via hole; and

a second via hole passing through the rear substrate, wherein the plurality of second interconnections are electrically connected with the plurality of second transparent electrodes corresponding thereto via the second via hole.

9. A holographic three-dimensional (3D) image display apparatus comprising:

a first light source which emits a write beam;

an electric addressable spatial light modulator (EASLM) which modulates the write beam emitted from the first light source according to hologram information regarding a 3D image;

a second light source which emits a read beam;

an optically addressable spatial light modulator (OASLM) which receives the write beam modulated by the EASLM and modulates the read beam emitted from the second light source according to hologram information included in the modulated write beam; and

a scanning optical unit which projects the write beam modulated by the EASLM onto the OASLM,

wherein the OASLM comprises;

a plurality of divided light modulation segments arranged in a two-dimensional (2D) array;

a plurality of gaps disposed between the plurality of segments; and

a plurality of independent transparent electrodes and a plurality of independent interconnections, wherein one of the plurality of independent transparent electrodes and one of the plurality of independent interconnections is connected to each of the plurality of segments, such that the plurality of segments can be turned on/off independently of any other of the plurality of segments.

10. The holographic 3D image display apparatus of claim 9, further comprising a Fourier lens which focuses the read beam modulated by the OASLM.

11. The holographic 3D image display apparatus of claim 9, wherein the EASLM is configured to sequentially modulate the write beam according to hologram information spatially divided into a plurality of regions corresponding to the plurality of segments of the OASLM, and

the scanning optical unit is configured to sequentially project the sequentially modulated write beams onto the plurality of corresponding segments of the OASLM.

12. The holographic 3D image display apparatus of claim 11, wherein the scanning optical unit is configured to project the modulated write beam onto only a region of each segment, wherein the region of each segment is less than an entire segment.

13. A holographic three-dimensional (3D) image display method comprising:

generating a hologram of a complete 3D image;

dividing the hologram into a plurality of sub-holograms respectively corresponding to a plurality of divided light modulation segments of an optically addressable spatial light modulator (OASLM), and discarding a region of the hologram corresponding to gaps disposed between the plurality of segments of the OASLM;

optimizing each of the plurality of sub-holograms;

sequentially providing the optimized sub-holograms to an electric addressable spatial light modulator (EASLM);

the EASLM modulating a write beam according to the optimized sub-holograms;

sequentially projecting the modulated write beam onto the plurality of segments of the OASLM corresponding to the respective sub-holograms;

the OASLM modulating a read beam according to the modulated write beam; and

generating the 3D image by projecting the read beam modulated by the OASLM.

14. The holographic 3D image display method of claim 13, wherein the OASLM comprises:

the plurality of divided light modulation segments arranged in a two-dimensional (2D) array;

the plurality of gaps disposed between the plurality of segments;

a plurality of independent transparent electrodes and a plurality of independent interconnections, wherein one of the plurality of independent transparent electrodes and one of the plurality of independent interconnections is connected to each of the plurality of segments, such that each of the plurality of segments can be turned on/off independent of any other of the plurality of segments.

15. The holographic 3D image display method of claim 13, wherein the hologram is a computer-generated hologram, and the generating the hologram comprises generating the hologram using one of a ping-pong algorithm, a coherent ray trace method, and a diffraction-specific algorithm.

16. The holographic 3D image display method of claim 13, wherein the plurality of sub-holograms and the plurality of segments of the OASLM are arranged in corresponding two-dimensional arrays.

17. The holographic 3D image display method of claim 13, wherein the optimizing each of the plurality of sub-holograms comprises binarizing the plurality of sub-holograms with respect to one of an amplitude and a phase according to modulation characteristics of the OASLM.

18. The holographic 3D image display method of claim 13, wherein the optimizing each of the plurality of sub-holograms comprises optimizing the plurality of sub-holograms using one of an iterative algorithm, a projection onto constrained sets algorithm, and a direct binary search algorithm.

19. The holographic 3D image display method of claim 13, wherein the modulated write beam is projected onto only a segment region of each segment of the OASLM, wherein the region of each segment is less than an entire segment.

20. The holographic 3D image display method of claim 13, wherein optimizing each of the plurality of sub-holograms comprises optimizing a sub-hologram corresponding to one of the plurality of segments while, at the same time, the modulated write beam is projected onto a previous segment of the OASLM.

21. The holographic 3D image display method of claim 13, wherein the sequentially projecting the modulated write beam onto the plurality of segments of the OASLM comprises turning on a segment of the OASLM onto which the write beam is currently incident and turning off all segments of the OASLM onto which the write beam is not currently incident.