Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/12—Stencil printing; Silk-screen printing

Definitions

• This invention relates to a method of making a color filter array element which is temperature-resistant and fade-resistant
• a line-type thermal printing head is used to apply heat from the back of the dye-donor sheet
• the thermal printing head has many heating elements and is heated up sequentially in response to the cyan, magenta and yellow signals. The process is then repeated for the other two colors. A color hard copy is thus obtained which corresponds to the original picture viewed on a screen. Further details of this process and an apparatus for carrying it out are contained in U.S. Patent No. 4,621,271.
• One commercially available type of color filter array element that has been used in liquid crystal display devices for color display capability is a transparent support having a gelatin layer thereon which contains dyes having the additive primary colors red, green and blue in a mosaic pattern obtained by using a photolithographic technique.
• a gelatin layer is sensitized, exposed to a mask for one of the colors of the mosaic pattern, developed to harden the gelatin in the exposed areas, and washed to remove the unexposed (uncrosslinked) gelatin, thus producing a pattern of gelatin which is then dyed with dye of the desired color.
• the element is then recoated and the above steps are repeated to obtain the other two colors. Further details of this process are disclosed in U.S. Patent 4,081,277.
• the color filter array element to be used therein may have to undergo rather severe heating and treatment steps during manufacture.
• a transparent conducting layer such as indium tin oxide (ITO)
• ITO indium tin oxide
• the curing may take place at temperatures as high as 200°C for times which may be as long as one hour or more.
• a thin polymeric alignment layer for the liquid crystals such as a polyimide
• Another curing step for up to several hours at an elevated temperature.
• the image When dry, the image was placed in a chamber filled with anisole vapor for 10 minutes and then baked in an oven at 133°F for 10 minutes. The plate was then washed with ethanol on the spinner and the resist removed by rubbing under hot water. The result was a clear image of blue dots corresponding to the photographic mask pattern.
• Example 4 The coated glass of Example 4 was covered by a metal mask with 5 mm holes in it and the assembly was placed beneath an infrared source (Model 5610 from Research Inc., Minneapolis, MN) at a distance of 15 cm for 4 minutes. Then the unfused cyan dye was removed by washing with water leaving a high contrast image of fused cyan dye corresponding to the holes in the mask.
• an infrared source Model 5610 from Research Inc., Minneapolis, MN
• the glass was then overcoated with a dispersion of the first magenta dye illustrated above (12%) in water by spinning at 5000 rev/min for 1 minute.
• the coated glass was placed on the heated aluminum post block for about 1 second, removed and washed with water to reveal the second color pattern.
• the glass was then coated with the third yellow illustrated above (12% in water), and the heating was repeated to give the third color pattern.
• Example 4 The coated glass of Example 4 was placed on an aluminum plate (0.64 cm thick) which had 4 holes drilled in it (0.64 cm diameter). The aluminum plate was placed over a well of methylene chloride for 10 seconds.

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Applications Claiming Priority (4)

Publications (1)

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Family Applications (1)

Country Status (2)

Citations (6)

• 1996
  • 1996-08-22 EP EP96420279A patent/EP0760487A1/fr not_active Withdrawn
  • 1996-08-29 JP JP22869496A patent/JPH09138305A/ja active Pending

Patent Citations (6)

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