Process and method employing dynamic holographic display medium

• US 6,178,018 B1
• Filed: 06/25/1999
• Issued: 01/23/2001
• Est. Priority Date: 06/25/1999
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kekas, Dennis Jason, Herlocker, Jon Alan, Loeb, Mitchell Levy
• Primary Examiner(s): SCHUBERG, DARREN E
• Application Number:
  US09/344,595
• Time in Patent Office: 578 Days
• Field of Search: 359/3, 359/9
• US Class Current: 359/9
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G02F 1/0558 structurally associated with a photoconductive layer or exhibiting photo-refractive properties
• CPC Class Codes: G03H 1/22 Processes or apparatus for obtaining an optical image from holograms G03H1/26 - G03H1/34 take precedence
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 2001/026 Recording materials or recording processes G03H2226/11 takes precedence; corresponding details, see subgroups of G03H2260/00
• CPC Class Codes: G03H 2001/0268 Inorganic recording material, e.g. photorefractive crystal [PRC]
• CPC Class Codes: G03H 2225/22 Electrically addressed SLM [EA-SLM]
• CPC Class Codes: G03H 2225/32 Phase only

Abstract

Conventional display technology can be used to display crude computer generated holograms (CGH), and can be extended to moving displays. However, the ones best suited from the standpoint of illumination flexibility, such as the common Liquid Crystal Displays (LCDs), switch very slowly. Thus systems with far better dynamic—rapid response requires very complex drive electronics. A non-memory ceramic PLZT, dynamic holographic display medium, provides much faster response time relative to common LCD technology. This system, which is the major embodiment of the present invention, also exhibits good spatial display capability. The system of the present invention, can display Fast Fourier Transformation (FFT) Computer Generated Holograms (CHHs); thus allowing the use of FFT based manipulation of images. By using a delta image updating in Fourier space, the instant system will speed up image generation significantly; since it is often the case that an object'"'"'s spatial frequency components change more slowly than its position.

Claims

1. A computer based dynamic holographic display system and medium, comprising:

a non-memory display material means based on PLTZ coated with a transparent photoconductive coating and covered with a transparent indium-tin-oxide electrode;

means for employing viewing optics with said non-memory holographic material, to display Fast Fourier Transformation computer generated holograms;

means of employing said Fast Fourier Transformation based manipulation of images to generate faster and refreshed said images, than attainable by Liquid Crystal Display Material.

2. The system of claim 1 wherein said PLTZ based system functions more rapidly than the comparable common Liquid Crystal Display material, for said display purpose.

3. The system of claim 1 wherein said PLTZ based system exhibits spatial display capabilities which are equal to or better than the comparable common Liquid Crystal Display material.

4. The system of claim 1 wherein said PLTZ based system displays Fast Fourier Transformation (FFT) Computer Generated Holograms (CHHs).

5. The system of claim 4 wherein said PLTZ based system displays facilitates the use of Fast Fourier Transformation based manipulation of images.

6. The system of claim 5 wherein said PLTZ based system wherein the use of a delta image updating in Fourier space, speeds up image generation.

7. The system of claim 1 wherein said PLZT holographic medium is derived from a mixture of metal oxides comprising lead, lanthanum, zirconium and titanium.

8. The system of claim 7 wherein said metal oxides are lead oxide (Pbo), lanthanum oxide (La2O3), Titanium Oxide (TiO2) and Zirconium Oxide (ZrO2).

9. The system of claim 8 wherein the Lanthanum Oxide can be replace with any other oxide in the periodic table of elements from the “

Lanthanide Series”

, which includes Cerium Ce, Praseodymium Pr, Neodymium Nd, Promethium Pm, Samarium Sm, Europium Eu, Gadolinium Gd, Terbium Tb, Dysprosium Dy, Holmium Ho, thulium tm, Ytterbium Yb, Lutetium Lu.

10. A computer based method for employing a dynamic holographic display medium, comprising the steps of:

providing a non-memory display medium based on PLZT, coated with a transparent photoconductive coating and covered with a transparent indium-tin-oxide electrode;

employing viewing optics with said non-memory material, to display Fast Fourier Transformation computer generated holograms;

employing said Fast Fourier Transformation based manipulation of images to generate faster and refreshed said images, than attainable by Liquid Crystal Display Material.

11. The method of claim 10 further comprising the steps of:

using said PLTZ based method to attain more rapid displays than the comparable common Liquid Crystal Display material can provide for display purpose.

12. The method of claim 10 further comprising the steps of:

employing said PLTZ based method to attain spatial display capabilities which are equal to or better than the comparable common Liquid Crystal Display material.

13. The method of claim 10, further comprising the steps of:

employing said PLTZ based method for displaying said Fast Fourier Transformation (FFT) Computer Generated Holograms (CHHs).

14. The method of claim 13 further comprising the steps of:

wherein said PLTZ based method to facilitate the use of said Fast Fourier Transformation based image manipulation.

15. The method of claim 10 further comprising the steps of:

using said PLTZ based method of a delta image updating in Fourier space, to speed up image generation.

16. The method of claim 10 further comprising the steps of:

employing said PLZT non-memory material, which is derived from a mixture of metal oxides comprising lead, lanthanum, zirconium and titanium.

17. The method of claim 16 wherein said metal oxides are lead oxide (Pbo), lanthanum oxide (La2O3), Titanium Oxide (TiO2) and Zirconium Oxide (ZrO2).

18. The method of claim 17 wherein the Lanthanum Oxide can be replace with any other oxide in the periodic table of elements from the “

Lanthanide Series”

, which includes Cerium Ce, Praseodymium Pr, Neodymium Nd, Promethium Pm, Samarium Sm, Europium Eu, Gadolinium Gd, Terbium Tb, Dysprosium Dy, Holmium Ho, thulium tm, Ytterbium Yb, Lutetium Lu.