Parallax compensating color filter and black mask for display apparatus

• US 20040070706A1
• Filed: 10/10/2002
• Published: 04/15/2004
• Est. Priority Date: 10/10/2002
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Freeman, Gary A.
• Granted Patent: US 7,388,631 B2
• Time in Patent Office: Days
• US Class Current: 349/110
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133567 on the back side

Abstract

A color display device comprising at least two substrates spaced from each other, the substrates each having an internal and an external surface, the internal surfaces of the two substrates facing each other, at least one of the substrates being transparent; electrodes positioned to establish a field in the space between the two substrates; an optically active material occupying at least a portion of the space between the two substrates and having optical properties influenced by the field; a color filter layer comprising color filter elements that alter the color of light traveling through the color filter layer, the color filter elements being positioned outside of the space between the two substrates; and a three-dimensional black mask comprising mask elements aligned with the boundaries between adjoining color filter elements. The three-dimensional black mask structure allows the color filter to be placed on the exterior of the display while still maintaining good color performance under off-axis viewing conditions.

Claims

1. A color display device comprising:

at least two substrates spaced from each other, the substrates each having an internal and an external surface, the internal surfaces of the two substrates facing each other, at least one of the substrates being transparent;

electrodes positioned to establish a field in the space between the two substrates;

an optically active material occupying at least a portion of the space between the two substrates and having optical properties influenced by the field;

a color filter layer comprising color filter elements that alter the color of light traveling through the color filter layer, the color filter elements being positioned outside of the space between the two substrates; and

a three-dimensional black mask comprising mask elements aligned with the boundaries between adjoining color filter elements.

2. The color display device of claim 1 wherein the three-dimensional black mask comprises at least two black mask layers.

4. The color display device of claim 2 wherein the three-dimensional black mask further comprises a third black mask layer.

5. The color display device of claim 4 wherein the black mask layers comprise at least one internal layer located between the two substrates and two external layers, each located either on an exterior surface of one of the two substrates or on another substrate external to the two substrates.

6. The color display device of claim 2 wherein the three-dimensional black mask has an aspect ratio of at least about 0.2.

7. The color display device of claim 4 wherein the three-dimensional black mask has an aspect ratio of at least about 0.2.

8. The color display device of claim 6 wherein the aspect ratio of the black mask is at least about 0.35.

9. The color display device of claim 7 wherein the aspect ratio of the black mask is at least about 0.5.

10. The color display device of claim 2 wherein the display device further comprises a third substrate supporting at least one black mask layer.

11. The color display device of claim 1 wherein the optically active material is an EO/MO material.

12. The color display device of claim 11 wherein the EO/MO material is a liquid crystal material.

13. The color display device of claim 1 wherein the color filter layer is formed by printing process.

14. The color display device of claim 1 wherein the color filter layer comprises multiple sub-layers, at least one for each different color.

15. The color display device of claim 1 wherein the color filter layer is formed on external surface of one of the two substrates.

16. The color display device of claim 1 wherein the color filter layers are formed on a third substrate laminated to the first and second substrates.

17. The color display device of claim 1 wherein the spacing in the normal direction between the optically active material and the color filter layer is greater than 1 mil.

18. The color display device of claim 1 wherein the two substrates each have a thickness in the range of about 20 μ

m to 500 μ

m.

19. The color display device of claim 18 wherein the two substrates each have a thickness in the range of about 30 μ

m to 250 μ

m.

20. The color display device of claim 19 wherein the two substrates each have a thickness in the range of about 50 μ

m to 150 μ

m.

3. The color display device of claim 3 wherein the black mask layers comprise at least one internal layer located between the two substrates and at least one external layer located either on an exterior surface of one of the two substrates or on another substrate external to the two substrates.

21. A method for manufacturing a color display device, the method comprising fabricating a display cell from at least two substrates, wherein the substrates each have an internal and an external surface, the internal surfaces of the two substrates face each other, at least one of the substrates being transparent, and wherein electrodes are positioned to establish a field in the space between the two substrates, and wherein an optically active material occupies at least a portion of the space between the two substrates and has optical properties influenced by the field;

testing the performance of the display cell; and

adding a color filter layer to the display cell only if the display cell passes the performance test, wherein the color filter layer is located exterior of the display cell.

22. The method of claim 21 further comprising adding a three-dimensional black mask comprising at least one black mask layer following testing of the performance of the display cell.

23. A display device comprising:

at least two substrates spaced from each other, the substrates each having an internal and an external surface, the internal surfaces of the two substrates facing each other, at least one of the substrates being transparent;

electrodes positioned to establish a field in the space between the two substrates;

an optically active material occupying at least a portion of the space between the two substrates and having optical properties influenced by the field;

a continuous seal is formed between the two substrates creating a cavity between the two substrates and circumscribed by the seal perimeter;

at least one fill port in the form of a hole in one or both of the substrates within the inner area of the seal perimeter, through which optically active material can be inserted into the space between the two substrates;

a flexible film cover overlying and sealed to the fill port,

wherein the film cover and fill port are sized and positioned so that a predetermined quantity of optically active material may be sealed in place inside the film cover after the space between the substrates is evacuated, and so that the film cover will deflect inwardly at the fill port to force the optically active material into the space between the substrates when the device is exposed to ambient pressure.

24. The display device of claim 23 wherein the optically active material is liquid crystal material.

25. The display device of claim 23 further comprising a second flexible film cover overlying and sealed to the film port, and the first mentioned and second film covers and the film port are sized and positioned so that the predetermined quantity of optically active material is positioned between the two film covers, and an opening is provided on the interior of the two film covers so that the optically active material may flow through the opening into the space between the two substrates when the film covers are deflected inwardly by the device being exposed to ambient pressure.