Diffusion barrier layers with microstructured spacing members for liquid crystal display panel substrates

• US 6,166,797 A
• Filed: 08/08/1997
• Issued: 12/26/2000
• Est. Priority Date: 08/08/1997
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Bruzzone, Charles L., Padiyath, Raghunath, Aastuen, David J. W., Thomas, Patrick A., Pokorny, Richard J., Gardner, Timothy J.
• Primary Examiner(s): Dudek, James A.
• Application Number:
  US08/907,744
• Time in Patent Office: 1,236 Days
• Field of Search: 349/155, 349/156, 349/158
• US Class Current: 349/155
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence

Abstract

Substrate elements for making liquid crystal display devices are disclosed as well as display devices using such elements. A substrate element includes a base sheet having the desired optical properties and providing the structural stability for the substrate element. The substrate element further includes a microstructured barrier layer that protects the base sheet from adverse chemical reactions with the liquid crystal or alignment layer solvents. The microstructured barrier layer comprises a plurality of microstructured spacing members that provide precise, uniform spacing between the first substrate element and a second substrate element. A pair of substrate elements, at least one of which having a microstructured barrier layer, can thereby be mated to form a display device. The substrate elements of the present invention allow large area, high resolution displays to be fabricated which will provide uniform display properties throughout the display area.

Claims

1. A substrate element for use in a liquid crystal display comprising:

a base substrate comprising a material that reacts with a liquid crystal material;

a barrier layer disposed on the base substrate and selected to resist diffusion of the liquid crystal material the barrier layer having a plurality of microstructured spacing members extending from the substrate element; and

independently addressable electrodes positioned between the spacing members on the barrier layer.

2. The substrate element of claim 1, wherein the base substrate is polymeric.

3. The substrate element of claim 1, wherein the base substrate comprises a thermoplastic.

4. The substrate element of claim 1, wherein the barrier layer comprises an epoxy acrylate.

5. The substrate element of claim 1, wherein the barrier layer is curable by exposure to radiation.

6. The substrate element of claim 1, wherein the plurality of spacing members comprises a plurality of parallel ridges.

7. The substrate element of claim 1, wherein the plurality of spacing members comprises a plurality of post-like protrusions.

8. The substrate element of claim 1, wherein the spacing members extend an average amount in a range of 1 to 25 microns.

9. A liquid crystal display comprising:

a first half-cell and a second half-cell forming a pair of half-cells in overlying register with one another and confining a liquid crystal material therebetween, wherein the first half-cell comprises a base substrate comprising a material that reacts with the liquid crystal material, a barrier layer disposed on the base substrate and selected to resist diffusion of the liquid crystal material, the barrier layer having a plurality of microstructured spacing members extending from the substrate element, and a plurality of independently addressable electrodes positioned between the spacing members on the barrier layer.