Title of Invention

PORTABLE REAL TIME DIGITAL HOLOGRAPHIC SYSTEM

Abstract The present invention is related to the digital imaging of holograms and realtime generation of holographic interferograms and shearograms based on the principle of digital holography for NDT related applications. The system is of modular design, consisting of an optical recording head and an image processor with real time digital hologram processing softsware. The recording head includes a device to generate two coherent waves, devices to control the intensity of reference beam and to adjust the object illumination, a mechanism to combine the object and reference waves forming an interference pattern at the recording plane and CCD/CMOS sensor. The detection device transfers the data to a processor, which does the real time digital reconstruction of the holograms, holographic interferograms and shearograms, which are displayed in the monitor. This data is used for non-destructive evaluation. (Fig 2)
Full Text Abstract
"A portable digital holographic system "
The present invention is related to the digital imaging of holograms and realtime generation of holographic interferograms and shearograms based on the principle of digital holography for NDT related applications. The system is of modular design, consisting of an optical recording head and an image processor with real time digital hologram processing softsware. The recording head includes a device to generate two coherent waves, devices to control the intensity of reference beam and to adjust the object illumination, a mechanism to combine the object and reference waves forming an interference pattern at the recording plane and CCD/CMOS sensor. The detection device transfers the data to a processor, which does the real time digital reconstruction of the holograms, holographic interferograms and shearograms, which are displayed in the monitor. This data is used for non-destructive evaluation.
(Fig 2)
We claim:
1. A portable digital holographic system for in-situ Non Destructive Testing (NDT) of large structures in real time, comprising a laser source (1), a coupler cum splitter (2) through which the laser beam passes, a recording head (3) having a CCD/CMOS sensor for digitizing the interference pattern, a real time processing module (4), consisting of digital hologram processing software, for real time numerical reconstruction of holograms, numerical shearing of holograms, generation of interferograms and shearograms and a monitor (7) for displaying the resulting interferograms.
2. The system as claimed in claim 1 wherein the said recording head (3) in addition comprises a beam attenuator (6b) for controlling the reference beam intensity emitted by the coupler (C) of the coupler cum splitter (2), a beam combiner (6a) for combining the reference beam and the beam received due to the light scatter from the object, and a lens (5) for imaging large objects.
3. The system as claimed in claim 1 wherein provisions are made on a base plate (BP) to mount the recording head (3) on a tripod (T).
4. The system as claimed in claim 1, wherein provision is made for connecting said recording head to any laser through optical fibers.
5. The system as claimed in claim 1 wherein said system is adapted to generate displacement fringes and displacement derivative fringes.
6. The system as claimed in claim 1 wherein said system is adapted to generate shearograms using numerical shearing.

7. The system as claimed in claim 1 wherein in a double exposure mode, the system is adapted to simultaneously provide both interferogram and shearogram of the object under stress.
8. A portable digital holographic system for in-situ Non Destructive Testing (NDT) of large structures in real time as hereinabove described with reference to the accompanying drawings.


Documents:

0679-che-2007-abstract.pdf

0679-che-2007-claims.pdf

0679-che-2007-correspondnece-others.pdf

0679-che-2007-description(complete).pdf

0679-che-2007-drawings.pdf

0679-che-2007-form 1.pdf

0679-che-2007-form 26.pdf

0679-che-2007-form 3.pdf

0679-che-2007-form9.pdf

679-CHE-2007 AMENDED PAGES OF SPECIFICATION 06-04-2011.pdf

679-CHE-2007 CORRESPONDENCE OTHERS 06-04-2011.pdf

679-CHE-2007 AMENDED CLAIMS 11-08-2010.pdf

679-che-2007 amended claims 31-01-2011.pdf

679-CHE-2007 EXAMINATION REPORT REPLY RECEIVED 11-08-2010.pdf

679-CHE-2007 CORRESPONDENCE OTHERS 31-01-2011.pdf


Patent Number 247506
Indian Patent Application Number 679/CHE/2007
PG Journal Number 15/2011
Publication Date 15-Apr-2011
Grant Date 12-Apr-2011
Date of Filing 30-Mar-2007
Name of Patentee INDIAN SPACE RESEARCH ORGANISATION
Applicant Address ISRO HEADQUARTERS,DEPARTMENT OF SPACE,ANTARIKSH,NEW BEL ROAD BANGALORE 560094
Inventors:
# Inventor's Name Inventor's Address
1 BINU PANACKAPARAMBIL THOMAS C/O VIKRAM SARABHAI SPACE CENTRE, THIRUVANANTHAPURAM-695 022
2 SUBRAMONIA PILLAI ANNAMALA PILLAI C/O VIKRAM SARABHAI SPACE CENTRE, THIRUVANANTHAPURAM-695 022
PCT International Classification Number G11B7/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA