Liquid crystal display

• US 20020167619A1
• Filed: 05/13/2002
• Published: 11/14/2002
• Est. Priority Date: 05/11/2001
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Delamarche, Emmanuel, Schmid, Heinz, Bietsch, Alexander, Michel, Bruno
• Granted Patent: US 6,798,464 B2
• Time in Patent Office: Days
• US Class Current: 349/1
• CPC Class Codes: G02F 1/133548 Wire-grid polarisers
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making

Abstract

A liquid crystal display device includes a substantially transparent substrate layer between a grating layer and a pixel electrode that comprises a solid conductor and an electrically conductive mesh. The device also includes a liquid crystal layer between said pixel electrode and a substantially transparent counter electrode that is arranged at a transparent cover plate. It further includes an active circuit element layer with a field effect transistor for controlling the pixel electrode. A method for manufacturing the liquid crystal display device is further disclosed wherein the pixel electrode is formed by printing a patterned substance onto the substrate layer and selectively plating a conductor onto said substance. The device may also comprise a conductor mesh comprising rows of conductor lines crossing with columns of conductor lines, wherein at least part of the conductor lines are randomly spaced from each other.

Claims

1. Liquid crystal display device comprising:

a substantially transparent substrate layer between a grating layer and a pixel electrode that comprises a solid conductor and an electrically conductive mesh,

a liquid crystal layer between said pixel electrode and a substantially transparent counter electrode that is arranged at a transparent cover plate,

an active circuit element layer with a field effect transistor for controlling the pixel electrode.

2. Liquid crystal display device according to claim 1, further comprising a light source for emitting light at a plurality of wavelength bands (R, G, B).

3. Liquid crystal display device according to claim 2, wherein the grating layer provides for a diffraction of the light.

4. Liquid crystal display device according to claim 1, wherein the electrically conductive mesh is connected to a gate of the field effect transistor.

5. Liquid crystal display device according to claim 1, wherein the electrically conductive mesh has a polarizing function for the light.

6. Liquid crystal display device according to claim 1, wherein the electrically conductive mesh comprises rows and/or columns of randomly spaced conductor lines.

7. Liquid crystal display device according to claim 1, wherein the liquid crystal layer comprises pillars or spacer balls.

8. Liquid crystal display device according to claim 1, wherein the counter electrode has a polarizing function for the light.

9. Liquid crystal display device according to claim 1, comprising an alignment layer for the alignment of liquid crystals in the liquid crystal layer.

10. Liquid crystal display device according to claim 1, wherein at the cover plate a diffusion layer is arranged.

11. Liquid crystal display device according to claim 1, wherein the grating layer comprises a chirped grating for providing for a separation of waveband components with different color.

12. Liquid crystal display device according to claim 11, wherein the grating layer is designed to focus the waveband components with different color onto individual pixels.

13. Liquid crystal display device according to claim 1, wherein the grating layer and/or the pixel electrode, comprise an electroless deposited (ELD) conductor.

14. Liquid crystal display device according to claim 1, wherein the pixel electrode has a transmittivity above 84%.

15. Liquid crystal display device according to claim 1, comprising a blocking layer for blocking a zero order wavelength band of the light.

17. The method of claim 16, further includes the step of providing a catalyst preferably comprising palladium (Pd) as the substance.

18. The method of claim 16, wherein the step for selectively plating conductor is an electroless metal deposition step being carried out in a plating bath.

20. The method of claim 19, wherein also the counter electrode is formed by the mentioned steps.

21. The method of claim 19, wherein a first stamp and a second stamp are employed, each stamp being mounted onto a cylinder of a printer, the first stamp and the second stamp being aligned with respect to each other in order for aligning the pixel electrode and the counter electrode with respect to each other.

22. The method of claim 19, comprising a soft lithography step for the formation of the counter electrode on the transparent cover plate.

23. The method of claim 19, wherein a polyimide sheet is deposited and rubbed, or an alignment layer is formed, in order to control the orientation of liquid crystals of the liquid crystal layer.

26. The conductor mesh of claim 25, wherein the conductor lines form a mesh with a lattice spacing (a) and wherein the conductor lines are about 10 times finer than said lattice spacing (a), preferably said conductor lines having a width of approximately 100 nm, and the lattice spacing (a) being approximately 1000 nm.

27. The conductor mesh of claim 25, comprising locally ordered lattices with different pitch, angle, and/or duty cycle.

28. The conductor mesh of claim 25, wherein the conductor lines are arranged such that the display has an angular function of light emitted normal to the mesh plane with a substantially flat intensity distribution in the viewing field.

29. The conductor mesh of claim 25, wherein the conductor lines are arranged such that the display has an angular function of light emitted towards with a defined cutoff outside of the viewing field.

30. The conductor mesh of claim 25, comprising a non evenly spaced, preferably randomly spaced, grating.

31. The conductor mesh of claim 25, comprising a randomly spaced grating and locally regular meshes with different lattice parameters, e.g. pitch.

32. The conductor mesh of claim 25, wherein the conductor lines are located at positions randomly varied around an average position.

33. The conductor mesh of claim 25, wherein the conductor lines comprise line segments with different length, each line segment being laterally displaced from a neutral position.

34. The conductor mesh according to claim 25, serving as an electrode or polarizer of the display.

16. Method for manufacturing a liquid crystal display device, that comprises a substantially transparent substrate layer between a grating layer and a pixel electrode that comprises a solid conductor and an electrically conductive mesh, a liquid crystal layer between said pixel electrode and a substantially transparent counter electrode that is arranged at a transparent cover plate, an active circuit element layer with a field effect transistor for controlling the pixel electrode,

wherein the pixel electrode (15, 120, 53) is formed by printing a patterned substance onto the substrate layer,

selectively plating a conductor onto said substance.

19. Method for manufacturing a liquid crystal display device, that comprises a substantially transparent substrate layer between a grating layer and a pixel electrode that comprises a solid conductor and an electrically conductive mesh, a liquid crystal layer between said pixel electrode and a substantially transparent counter electrode that is arranged at a transparent cover plate, an active circuit element layer with a field effect transistor for controlling the pixel electrode,

wherein the pixel electrode is formed by forming a homogeneous conductor layer onto the substrate layer,

printing a resist onto said homogeneous conductor layer defining the pixel electrode to be formed, and

selectively removing those areas of the homogeneous conductor layer that are not protected by said resist.

24. Display comprising a liquid crystal display device, said liquid crystal display comprises:

a substantially transparent substrate layer between a grating layer and a pixel electrode that comprises a solid conductor and an electrically conductive mesh,

a liquid crystal layer between said pixel electrode and a substantially transparent counter electrode that is arranged at a transparent cover plate, and

an active circuit element layer with a field effect transistor for controlling the pixel electrode.

25. Conductor mesh for use in a display, comprising rows of conductor lines crossing with columns of conductor lines, wherein at least part of the conductor lines are randomly spaced from each other.