Method and apparatus for testing operation of an optical liquid crystal device

Patent metadata

Field	Value
Publication number	US-9874774-B2
Application number	US-201514817275-A
Country	US
Kind code	B2
Filing date	Aug 4, 2015
Priority date	Oct 27, 2009
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

Methods and apparatus for testing operation of a single or multiple tunable active optical device(s) operated by one or more driving electrodes are described. Test methods and apparatus are provided for device testing without necessarily requiring direct physical contact with the driving electrodes. Testing subjects devices to incident light along an optical path and to an external electric field applied to the device producing a dipolar charge distribution within the electrodes, causing the device to operate. The effect of device operation on incident light is optically sensed. The sensed effect is analyzed to identify device defects. Test methods and apparatus are provided for testing multiple unsingulated devices during fabrication employing a strip contact structure having contact strips connected to multiple devices and extending to wafer edges, such that singulating devices leaves portions of the strip contact structure exposed on device dice edges providing electrical contacts in use.

First claim

What is claimed is:

1. An apparatus for testing operation of at least one electro-optical liquid crystal device having at least one driving electrode for operating said device, said apparatus comprising:
a light source for directing incident light toward said device substantially along an optical axis thereof;
an electrical arrangement for applying to said liquid crystal device an external electric field to produce a dipolar charge distribution within said electrode, causing operation of said liquid crystal device; and
an optical sensor responsive to an effect of said liquid crystal operation on said incident light.

2. The apparatus of claim 1 , wherein said at least one electro-optical liquid crystal device is included in a multiple unit further including a plurality of such electro-optical devices being tested in parallel using said apparatus.

3. The apparatus according to claim 2 , wherein said optical liquid crystal device is one of a tunable-focusing liquid crystal lens and a liquid crystal display cell.

4. The apparatus according to claim 2 , further comprising a data processor for analyzing the sensor response to identify any defective portion of said liquid crystal device.

5. The apparatus according to claim 2 , wherein said electrical arrangement includes at least one testing electrode connected to an electrical voltage source, said testing electrode being provided on a corresponding substrate.

6. The apparatus according to claim 5 , wherein said testing electrode is substantially planar and made of an optically transparent material.

7. The apparatus according to claim 6 , wherein each said substrate is made of an optically transparent material.

8. The apparatus according to claim 5 , wherein said testing electrode is configured to be disposed in a predetermined spaced relationship with said driving electrode to generate said external electric field at a predetermined voltage value.

9. The apparatus according to claim 8 , wherein said device has first and second opposed planar surfaces extending transversely with respect to said optical path, said incident light being directed through one of said first and second surfaces, and said optical effect being sensed from the other one said surfaces.

10. The apparatus according to claim 8 , wherein said device has first and second opposed planar surfaces extending transversely with respect to said optical path, said apparatus further comprising an optical reflecting layer disposed adjacent to one of said first and second surfaces, said incident light being directed through the other one of said surfaces, and said optical effect being sensed following reflection thereof on said layer from said adjacent surface through said other surface.

11. The apparatus according to claim 5 , wherein said device has first and second driving electrodes disposed in a predetermined spatial relationship with one another, said electrical arrangement including first and second testing electrodes connected to an electrical voltage source.

12. The apparatus according to claim 5 , wherein said first testing electrode is provided on a first substrate adapted to be disposed in a predetermined spaced relationship with said first driving electrode, a second testing electrode is provided on a second substrate adapted to be disposed in a predetermined spaced relationship with said second driving electrode, to generate said external electric field at a predetermined relative voltage value between said first and second driving electrodes.

13. The apparatus according to claim 12 , wherein said device has first and second opposed planar surfaces extending transversely with respect to said optical path, said incident light being directed respectively through one of said first and second substrates and one of said first and second surfaces, and said optical effect being sensed from the other one of said surfaces through the other one of said substrates.

14. The apparatus according to claim 12 , wherein said device has first and second opposed planar surfaces extending transversely with respect to said optical path, said apparatus further comprising an optical reflecting layer disposed adjacent to one of said first and second surfaces, said incident light being directed respectively through one of said first and second substrates and the other one of said surfaces, and said optical effect being sensed following reflection thereof on said layer from said adjacent surface through said other surface and said one of said first and second substrates.

Assignees

• Lensvector Inc

Inventors

• Afshari Bahram
• Asatryan Karen
• Clark Peter P
• Galstian Tigran
• Nystrom Michael J
• Presniakov Vladimir
• Yakovenko Sergei
• Zohrabyan Armen

Classifications

• Y10T29/49002

  Electrical device making · CPC title

• G02F1/133351 Primary

  Manufacturing of individual cells out of a plurality of cells, e.g. by dicing · CPC title

• G09G3/006

  Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays (testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309) · CPC title

• Y10T29/49771

  Quantitative measuring or gauging · CPC title

• G02F1/1309

  Repairing; Testing · CPC title