Method and machine for producing optical compensation sheet

• US 20030214059A1
• Filed: 05/09/2003
• Published: 11/20/2003
• Est. Priority Date: 05/13/2002
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Itoh, Hidetomo
• Granted Patent: US 7,208,194 B2
• Time in Patent Office: Days
• US Class Current: 264/1.1
• CPC Class Codes: B29B 13/023 Half-products, e.g. films, plates
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29C 2059/023 Microembossing
• CPC Class Codes: B29C 2059/027 Grinding; Polishing
• CPC Class Codes: B29C 39/18 incorporating preformed parts or layers, e.g. casting around inserts or for coating articles B29C39/206 takes precedence
• CPC Class Codes: B29C 59/022 characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: B29L 2011/00 Optical elements, e.g. lenses, prisms
• CPC Class Codes: B32B 2037/243 Coating
• CPC Class Codes: B32B 2305/55 Liquid crystals
• CPC Class Codes: B32B 2309/02 Temperature
• CPC Class Codes: B32B 2310/0454 Hot air
• CPC Class Codes: B32B 2457/20 Displays, e.g. liquid crystal displays, plasma displays
• CPC Class Codes: B32B 38/16 Drying; Softening; Cleaning
• CPC Class Codes: B32B 38/164 Drying
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation

Abstract

A film sheet which has a polymer layer formed of a coating solution is drawn from a balk roll and transported toward a rubbing apparatus. Thereby, first and second blowers sequentially disposed respectively apply to the polymer layer an air of temperature 45±2° C. and humidity 50%-60%, and an air of temperature 25±1° C. and humidity 30%-35%. Thus, damages which occurred in transporting and rolling the film sheet are removed. Thereafter, a rubbing action is performed to the film sheet such that the polymer layer has alignment. Then a liquid crystal layer is formed on the polymer layer, to obtain an optical compensation film.

Claims

1. A method for producing an optical compensation sheet from a continuous film, which is constructed of a transparent film base and a transparent polymer layer formed on said film base, comprising steps of:

(a) transporting said film;

(b) blowing a first air onto said polymer layer of said film upon transporting said film, said first air having dry bulb temperature between 30°

C. and 60°

C. and relative humidity between 55% and 80%;

(c) rubbing a surface of said polymer layer to form alignment on said polymer layer after step (b); and

(d) coating said polymer layer with a solution containing liquid crystal after step (c), so as to obtain said optical compensation sheet.

2. A method described in claim 1, wherein a discharge of said first air is almost uniform in a widthwise direction.

3. A method described in claim 2, further comprising a step of drawing said film from a film roll before step (a).

4. A method described in claim 3, wherein said film further includes an undercoat layer between said film base and said polymer layer in order to firmly form said polymer layer.

5. A method described in claim 1, further comprising a step of blowing a second air onto said polymer layer between steps (b) and (c), a relative humidity of said second air being between 30% and 50%.

6. A method described in claim 5, wherein a discharge of said second air is almost uniform in a widthwise direction.

7. A method described in claim 6, wherein dry bulb temperature of said second air is between 25°

C. and 30°

C.

8. A machine for producing an optical compensation sheet from a continuous film, which is constructed of a transparent film base and a transparent polymer layer formed on said film base, said machine comprising:

a transporting means for transporting said film;

a first blower for blowing a first air onto said polymer layer of said transported film, said first air having dry bulb temperature between 30°

C. and 60°

C. and relative humidity between 55% and 80%;

a rubbing means positioned downstream from said first blower, for rubbing said polymer layer to form alignment on said polymer layer; and

a liquid crystal layer forming means positioned downstream from said rubbing means, for forming a liquid crystal layer on said polymer layer to obtain said optical compensation sheet.

9. A machine described in claim 8, further comprising a second blower positioned between said first blower and said rubbing means, said second blower blowing onto said polymer layer a second air whose relative humidity is between 30% and 50%.

10. A machine described in claim 9, wherein said first blower is provided with a temperature/humidity controller for controlling the dry bulb temperature and the relative humidity of said first air.

11. A machine described in claim 10, wherein said first blower has an opening which is nearly rectangular, and said first air is blown through said opening.

12. A machine described in claim 11, wherein said film is drawn from a film roll.

13. A machine described in claim 12, wherein said film includes an undercoat layer between said film base and said polymer layer to firmly form said polymer layer.

14. A machine described in claim 9, wherein said second blower has a temperature/humidity controller for controlling the dry bulb temperature and the relative humidity of said second air.

15. A machine described in claim 14, wherein said transporting means includes a guide roller for bending a film path to be L-shaped, said first air blower being positioned upstream from said guide roller, and said second air blower being positioned downstream from said guide roller.

16. A machine described in claim 15, wherein dry bulb temperature of said second air is between 25°

C. and 30°

C.

17. A machine described in claim 16, wherein discharge of said second air is almost uniform in the widthwise direction.

18. A machine described in claim 17, wherein said second blower has an opening which is nearly rectangular, and said first air is blown through said opening.