Electro-optical element and its manufacturing method

• US 5,615,039 A
• Filed: 09/10/1991
• Issued: 03/25/1997
• Est. Priority Date: 09/10/1991
• Status: Expired due to Term

• Current Assignee: Photon Dynamics Incorporated (KLA Corporation)
• Original Assignee: Photon Dynamics Incorporated (KLA Corporation)
• Inventors: Henley, Francois J.
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): Robbins, Thomas
• Application Number:
  US07/757,454
• Time in Patent Office: 2,023 Days
• Field of Search: 359/226, 359/227, 359/257, 359/267, 359/275
• US Class Current: 359/257
• CPC Class Codes: G02F 1/0305 Constructional arrangements G02F1/0327 - G02F1/05 take precedence
• CPC Class Codes: G02F 1/1309 Repairing; Testing
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/136254 Checking; Testing

Abstract

The present invention provides an electro-optical element and its manufacturing method ideal for use in defect inspection devices for liquid crystal display substrates used in liquid crystal display panels. The electro-optical element of this invention possesses an electro-optical element, dielectric reflective film, transparent electrode, and transparent supporting substrate. These are united together by adhering the dielectric reflective film and transparent electrode edge to the electro-optical element. The electro-optical element is manufactured by consecutively affixing the transparent sheet with the transparent electrode, the electro-optical element, and transparent film with the dielectric reflective film to the transparent supporting substrate. Since the electro-optical element of this invention is equipped with a transparent electrode and dielectric reflective film, the optical properties of the electro-optical element change by the transmission of electricity to the transparent electrode and inspected body and creation of an electric field, and it can be used in defect inspection of an inspected body by measuring those changes.

Claims

1. An electro-optical element which possesses properties which change when an electric field is impressed across it, said electro-optical element comprising an electro-optical layer comprising a top surface, a bottom surface, and an electro-optical layer edge a dielectric reflective film overlying said bottom surface of said electro-optical layer, a transparent electrode overlying said top surface of said electro-optical layer, transparent supporting substrate overlying said transparent electrode, said transparent supporting substrate including an edge portion, and an adhesive layer formed overlying said electro-optical layer edge and said edge portion of transparent supporting substrate, wherein said adhesive layer affixes said electro-optical layer with said transparent supporting substrate.

2. A partially completed electro-optical element comprising:

electro-optical material comprising a top surface, a bottom surface, and an edge;

a transparent sheet comprising a first transparent sheet side and a second transparent sheet side, said transparent sheet being coated with a transparent electrode on said first transparent sheet side, said transparent electrode overlying said top surface of said electro-optical material;

a transparent film with a dielectric reflective film on one side thereof, said transparent film comprising an other side, said other side overlying said bottom surface of said electro-optical element;

a transparent supporting substrate comprising a substrate edge overlying said second transparent sheet side, said transparent film being larger than the transparent supporting substrate, and said transparent supporting substrate being within a perimeter of said transparent film; and

an adhesive film applied between said edge of said electro-optical material, said substrate edge, and a portion of said transparent film.

3. The electro-optical element as described in claim 2 in which said transparent conductive layer is a layer of indium trioxide.

4. The electro-optical element as described in claim 2 in which said reflective film is comprised of a plurality of layers of material alternately composed of a low refractive index material, and a high refractive index material.

5. The electro-optical element as described in claim 2 in which said reflective layer is further comprised of an electrically conductive material, and divided into individual segments, each segment corresponding to a single segment or pixel of the device to be tested.

6. The electro-optical element as described in claim 2 in which the electro-optical material between said first transparent sheet and said second transparent sheet does not contain any voids or bubbles.

7. The electro-optical element as described in claim 2 in which said electro-optical material located between said first transparent sheet and said second transparent sheet is comprised of Pockels crystalline material.

8. The electro-optical element as described in claim 2 in which the electro-optical material located between said first transparent film and said second transparent film is further comprised of nematic curvilinear aligned phase (NCAP) material.

9. The electro-optical element as described in claim 2 in which said first transparent film is further comprised of a polyethylene terephthalate film.

10. The electro-optical element as described in claim 2 in which said second transparent film is further comprised of a polyethylene terephthalate film.

11. An electro-optical element comprising:

a first transparent sheet having first and second sides;

a transparent conductive layer located on said second side of said transparent sheet;

an electro-optical element material whose optical properties with respect to light transmisivity change when an electric field is applied across the electro-optical material located on said first side of said first transparent sheet;

a second transparent sheet having first and second sides, said first side of said second transparent sheet being placed adjacent to said electro-optical material, said first side of said second transparent sheet facing said first side of said first transparent sheet, and separated from said first transparent sheet by said electro-optical material, said electro-optical material effectively encapsulated between said first transparent sheet and said second transparent sheet;

a reflective film located on said second side of said second transparent sheet;

said first transparent sheet and said second transparent sheet bonded together along the edges thereof by an adhesive, said first transparent sheet and said second transparent sheet free from said adhesive at surfaces thereof.

12. The electro-optical element as described in claim 11 in which said transparent conductive layer is a layer of indium trioxide.

13. The electro-optical element as described in claim 11 in which said reflective film is comprised of a plurality of layers of material alternately composed of a low refractive index material, and a high refractive index material.

14. The electro-optical element as described in claim 11 in which the electro-optical element is a thin, planar element.

15. The electro-optical element as described in claim 11 in which said reflective layer is further comprised of an electrically conductive material, and divided into individual segments, each segment corresponding to a single segment or pixel of the device to be tested.

16. The electro-optical element as described in claim 11 in which the electro-optical material between said first transparent sheet and said second transparent sheet does not contain any voids or bubbles.

17. The electro-optical element as described in claim 11 in which said electro-optical material located between said first transparent sheet and said second transparent sheet is comprised of Pockels crystalline material.

18. The electro-optical element as described in claim 11 in which the electro-optical material located between said first transparent film and said second transparent film is further comprised of nematic curvilinear aligned phase (NCAP) material.

19. The electro-optical element as described in claim 11 in which said first transparent Sheet is further comprised of a polyethylene terephthalate film.

20. The electro-optical element as described in claim 11 in which said second transparent sheet is further comprised of a polyethylene terephthalate film.

21. A method of forming an electro-optic element comprising the steps of:

providing a first sheet comprising a first inner face and a first outer face, and a second sheet comprising a second inner face and a second outer face;

applying an electrode overlying said first inner face;

affixing an electro-optical layer between said second inner face and said electrode overlying said first inner face; and

adhering said first outer face to a supporting substrate.

22. The method of claim 21 wherein said adhering step occurs with an optical adhesive having light transmission characteristics and being free from particles.

23. The method of claim 22 wherein said adhering step comprise applying uniform force onto said electro-optical element until said optical adhesive hardens.

24. The method of claim 23 further comprising a step of removing said second sheet from said electro-optical material.

25. The method of claim 24 further comprising a step of affixing a dielectric film overlying said electro-optical material.

26. The method of claim 25 wherein said dielectric film is a liquid glass selected from a group consisting of silicon trioxide or titanium trioxide.

27. The method of claim 25 wherein said dielectric film comprise a first thin film with a refractive index and a second thin film with a refractive index higher than that of the first thin film.

28. The method of claim 25 wherein said affixing step occurs with an optical adhesive having light transmission characteristics and free from particles.

30. The method of claim 25 wherein said dielectric film adheres to edges around said electro-optical element with said adhesive.

31. The method of claim 35 wherein said dielectric film comprise a reflective material.

32. The method of claim 31 wherein said dielectric film comprise a thickness of about 2 micrometers.

33. The method of claim 21 wherein said first and said second sheet comprise polyethylene terephthalate.

34. The method of claim 21 wherein said electrode comprise indium trioxide.

35. The method of claim 21 wherein said electro-optical layer includes a thickness of about 20 micrometers.

36. The method of claim 21 wherein said electro-optical material comprises Nematic Curvilinear Aligned Phase sheets.

37. The method of claim 27 wherein said electro-optical material comprises Pockel crystals.

29. The method of claim 29 wherein said step of affixing further comprise applying a uniform force onto said electro-optical material until said optical adhesive hardens.