Method of making a display

Details Method of making a display Method of making a display

1998-03-30

2001-06-12

Pianalto, Bernard (Department: 1762)

Coating processes

Direct application of electrical, magnetic, wave, or...

Polymerization of coating utilizing direct application of...

C427S256000, C427S385500, C427S558000, C427S559000

Reexamination Certificate

active

06245393

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to display devices, and more particularly to multicolor display devices having fluorescent dyes deposited by ink jet printing.
BACKGROUND OF THE INVENTION
Display devices utilizing fluorescent media capable of absorbing light and emitting it at a longer wavelength are known. See, e.g., U.S. Pat. No. 5,294,870 to Tang et al., entitled “Organic Electroluminescent Multicolor Image Display Device,” the entire disclosure of which is hereby incorporated by reference. However, the fluorescent media in such devices are deposited using patterning techniques such as photolithography which are costly to perform. Hence, there exists a need for a method by which fluorescent media can be inexpensively and accurately deposited on a substrate to produce a multicolor display device.
SUMMARY OF THE INVENTION
The present invention is directed to display devices, each comprising a substrate and fluorescent dye deposited onto the substrate. The present invention further includes methods of making such display devices utilizing ink jet printing techniques. Such devices are advantageous in that the fluorescent dye can be deposited cheaply, over very large or very small areas, with a high degree of resolution. Consequently, they can be used in practically any application where display devices are presently used.
In one embodiment of the present invention, red, green and/or blue fluorescent dyes are ink jet printed onto a transparent substrate to create an image with a predetermined configuration. The thus-created image is thereafter exposed to ultraviolet or other short wavelength radiation to activate the dyes and create a luminous color display. Such a display is “passive” in the sense that the image is fixed in the as-printed configuration.
In another embodiment of the present invention, red, green and/or blue fluorescent dyes are again ink jet printed in a predetermined configuration onto a transparent substrate. A layer of transparent, conductive material is then deposited over the dyes. A layer of organic, blue light emitting device (OBLED) is thereafter deposited over the layer of transparent conductive material, and a conductive layer is deposited over the OBLED layer. Application of a potential across the conductive layers illuminates the OBLED layer, producing a blue emission, which stimulates fluorescent emission in the dyes, so long as the energy of the blue emission is greater than the emission of the dyes.
In another embodiment of the present invention, red, green and blue light emitting regions are ink jet printed in a predetermined configuration onto a transparent substrate. The red and green light emitting regions are formed by ink jet printing red and green fluorescent dyes onto the substrate. No ink is deposited in the blue light emitting regions. Rather, the blue light emitting regions are left as empty spaces while the red and green fluorescent dyes are printed. After the red and green dyes are printed, a layer of transparent, conductive material is deposited over the red and green dyes and the empty spaces left for the blue light emitting regions. A layer of organic, blue light emitting device (OBLED) is thereafter deposited onto the layer of transparent, conductive material. Electrical contacts are then placed on the OBLED in each of the red, green and blue light emitting regions, to facilitate the application of voltage across the OBLED. The OBLED produces a blue emission in the blue light emitting regions, and further, stimulates fluorescent emission in the red and green light emitting regions thereby creating a luminous color display. In this embodiment, the red and green dyes preferably have strong absorption in the blue, and preferably further have high blue-to-red and blue-to-green conversion efficiencies.
In a further embodiment of the present invention, red, green and blue light emitting regions are ink jet printed in the form of pixels onto a transparent substrate. Each pixel has one of each of a red, green and blue light emitting region. This fourth embodiment is made in a manner similar to the third embodiment, the primary difference being that the light emitting regions of the fourth embodiment are arranged in tri-color pixels whereas the light emitting regions of the third embodiment are arranged in some predetermined configuration.
The displays of the present invention can be used in a wide variety of products including a computer, a television, a telecommunications device which incorporates a screen such as a telephone, a vehicle, a billboard or sign, or a large area wall, theater or stadium screen. Moreover, because the display devices of the present invention can be made using any sufficiently flat substrate, it is contemplated the devices can be used in xerography, thereby eliminating the need for lensing in printer bars.


REFERENCES:
patent: 4243694 (1981-01-01), Mansukhani
patent: 4292107 (1981-09-01), Tanaka et al.
patent: 4446174 (1984-05-01), Maekawa et al.
patent: 4651053 (1987-03-01), Kato et al.
patent: 4668533 (1987-05-01), Miller
patent: 5059266 (1991-10-01), Yamane et al.
patent: 5064711 (1991-11-01), Ito et al.
patent: 5114744 (1992-05-01), Cloutier et al.
patent: 5132248 (1992-07-01), Drummond et al.
patent: 5204055 (1993-04-01), Sachs et al.
patent: 5247315 (1993-09-01), Phelan et al.
patent: 5260009 (1993-11-01), Penn
patent: 5266098 (1993-11-01), Chun et al.
patent: 5294870 (1994-03-01), Tang et al.
patent: 5324359 (1994-06-01), Cleveland
patent: 5340656 (1994-08-01), Sachs et al.
patent: 5387380 (1995-02-01), Cima et al.
patent: 5403617 (1995-04-01), Haaland
patent: 5459502 (1995-10-01), Sakaki et al.
patent: 5478381 (1995-12-01), Ohiwa et al.
patent: 5485188 (1996-01-01), Tochihara et al.
patent: 5495803 (1996-03-01), Gerber et al.
patent: 5753352 (1998-05-01), Vanmaele et al.
patent: WO 96/19792 (1996-06-01), None
Hosokawa et al., “Highly efficient blue electroluminescence from a distrrylarylene emitting layer with a new dopant,” 67Appl. Phys. Lett. 3853-3855 (Dec. 1995).
Adachi et al., “Blue light-emitting organic electroluminescent devices,” 56Appl. Phys. Lett. 799-801 (Feb. 1990).
H. Vestweber et al., “Electroluminescense from polymer blends and molecularly doped polymers,” 64Synthetic Metals141-145 (1994). (No month avail).
Burrows et al., “Color tunable Organic Light Emitting Devices,” 69Appl. Phys. Lett. 2959 (Nov. 11, 1996).
Johnson et al., “Electroluminescence from single layer molecularly doped polymer films”, 67Pure&Appl. Chem. pp. 175-182 (1995). (No month avail).

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