DISPLAY DEVICE, PRODUCTION AND USE THEREOF

Abstract

The present invention relates to a display device, in particular a backlit display device having a visible side and a back side, which appears opaque in colour and texture on viewing of the visible side without backlighting, but, with the backlighting switched on, is sufficiently transparent that the transmission of information by the light source from the back side is possible, and to the production of a display device of this type and to the use thereof.

Claims

1. Display device comprising a transparent substrate having a visible side and a back side, a coating on the visible side of the transparent substrate and a light source which is integrated into the transparent substrate or arranged on the back of the transparent substrate, where the coating comprises at least one transparent binder, at least one colourless, transparent, flake-form interference pigment and at least one absorption pigment and optionally further additives, and where the coating, when applied over the entire area to a black/white background in a layer thickness of 14±2 μm and measured spectrophotometrically at an illumination angle of 45° and at a viewing angle of 75°, has a colour separation ΔE* between the coated black background and the coated white background in the range from 3 to 35.

2. Display device according to claim 1, characterised in that the interference pigment(s) and absorption pigment(s) are present in the coating in a ratio of 1:1 to 10:1.

3. Display device according to claim 2, characterised in that the ratio of interference pigment(s) to absorption pigment(s) in the coating is 1.5:1 to 8:1.

4. Display device according to claim 1, characterised in that the colourless, transparent, flake-form interference pigment is a pigment which has a colourless, transparent, flake-form support selected from the group consisting of natural or synthetic mica, talc, kaolin, sericite, SiO.sub.2, Al.sub.2O.sub.3, TiO.sub.2 and glass, where the flake-form support is coated with at least one colourless metal oxide layer and the metal oxides are selected from the group consisting of SiO.sub.2, Al.sub.2O.sub.3, TiO.sub.2, ZrO.sub.2, SnO.sub.2 und ZnO.

5. Display device according to claim 1, characterised in that the colourless, transparent, flake-form interference pigment has a volume-weighted d.sub.10 value of the particle size between 5 μm and 10 μm and a volume-weighted d.sub.90 value of the particle size between 105 and 180 μm.

6. Display device according toclaim 1, characterised in that the absorption pigment is at least one inorganic or organic absorption pigment having a median value of the primary particle size in the range from 10 nm to 500 nm.

7. Display device according to claim 1, characterised in that the coating comprises no further colouring ingredients apart from the at least one colourless, transparent, flake-form interference pigment and the at least one absorption pigment.

8. Display device according to claim 1, characterised in that the at least one colourless, transparent interference pigment and the at least one absorption pigment together have a proportion of 15 to 40% by weight, based on the total weight of the coating.

9. Display device according to claim 1, characterised in that the transparent substrate is a plastic film, a plastic body, a glass sheet, a glass body or a transparent layer on a light source.

10. Display device according to claim 1, characterised in that the coating has been applied directly to a substrate surface forming the visible side of the transparent substrate.

11. Display device according to claim 10, characterised in that the coating has been applied to the entire area of the substrate surface forming the visible side of the transparent substrate.

12. Display device according to claim 10, characterised in that the substrate surface forming the visible side of the transparent substrate has first and second part-areas, where the coating has been applied to the first part-area and the first part-area has a shape which itself represents information, and where the second part-area has been provided with a masking layer that is opaque to light.

13. Display device according to claim 1, characterised in that the light source is arranged on the back of the transparent substrate and a masking layer which is partly transparent to light and partly opaque to light is arranged between the light source and the transparent substrate.

14. Display device according to claim 1, characterised in that a masking layer which is partly transparent to light and partly opaque to light is arranged between a substrate surface forming the visible side of the transparent substrate and the coating.

15. Display device according to claim 1, characterised in that the coating has a layer thickness in the range from 5 to 60 μm.

16. Display device according to claim 1, characterised in that the light source is a light source emitting white or coloured light, selected from the group consisting of incandescent lamps, cold-light lamps, warm-light lamps, fibre-optical systems, fluorescent lamps, energy-saving lamps, LEDs, OLEDs, OLECs and displays of electronic devices.)

17. Display device according to claim 1, characterised in that the light source has an emission maximum in a certain wavelength range of light and the colourless, transparent, flake-form interference pigment has a transmission maximum in a certain wavelength range of light and in that the emission maximum of the light source and the transmission maximum of the interference pigment are in the same wavelength range of light.

18. Display device according to claim 1, characterised in that the display device as part of an object is integrated into the latter in a form-fitting manner and the visible side of the transparent substrate which is provided with the coating forms a common surface with the object, where the common surface has uniform colour, gloss and/or texture effects when the light source is switched off.

19. Process for the production of a display device according to claim 1, characterised in that a surface which forms a visible side of a two-dimensional transparent substrate, where a light source has optionally been integrated into the substrate and where the surface has optionally been pre-coated with a masking layer which is partly transparent to light and partly opaque to light, is coated with a coating composition which comprises at least one transparent binder, at least one colourless, transparent, flake-form interference pigment, at least one absorption pigment and optionally further additives, where interference pigment(s) and absorption pigment(s) are present in the coating composition in a ratio of 1:1 to 10:1, the coating composition is subsequently solidified, and, in the case where the substrate does not contain a light source, a light source is arranged on the back of the transparent substrate.

20. Process according to claim 19, characterised in that the coating composition is applied to the entire area of the two-dimensional transparent substrate.

21. Process according to claim 19, characterised in that the surface of the two-dimensional transparent substrate has not been pre-coated with a masking layer and the coating composition is applied to a first part-area of the surface of the two-dimensional transparent substrate, which has a shape which itself represents information, and where a second part-area of the surface of the two-dimensional transparent substrate which supplements the first part-area is provided with a masking layer that is opaque to light, so that the entire surface of the two-dimensional transparent substrate is coated.

22. Process according to claim 19, characterised in that the coating composition comprises no further colouring ingredients apart from the at least one colourless, transparent, flake-form interference pigment and the at least one absorption pigment.

23. Process according to claim 19, characterised in that a coating is obtained which, after solidification, has a dry layer thickness in the range from 5 to 60 μm.

24. Process according to claim 19, characterised in that the coating composition is an automotive paint.

25. A static or variable, backlit information display for interior and/or exterior components of motor vehicles, for domestic appliances, electronic devices, architectural elements, advertising areas, information panels, direction signs, furniture, decoration elements for the interior and exterior design of buildings or for objects of art, comprising the display device according to claim 1.

26. The static or variable, backlit information display for interior and/or exterior components of motor vehicles, for domestic appliances, electronic devices, architectural elements, advertising areas, information panels, direction signs, furniture, decoration elements for the interior and exterior design of buiildings or for objects of art according to claim 25, characterised in that it is a variable information display and the type of information, the duration and frequency of the emission of the information or the light strength of the information is controlled by an electronic programme.

Description

[0074] If the display device according to the invention is a variable information display, the type of information, the duration and frequency of the emission of the information and the light strength of the information can be controlled by an electronic program. This gives rise to a large band width of possible uses with individually selectable area dimensions of the display device in a very broad range.

[0075] FIG. 1: shows the transmission, reflection and absorption spectrum of the pigment Pyrisma Turquoise SW

[0076] FIG. 2: shows the emission spectrum of a blue OLED W1832

[0077] The present invention is intended to be explained in greater detail below with reference to examples, but not reduced thereto.

EXAMPLE 1

[0078] Coloured paints (A) (B) and (C) having the following composition are prepared:

TABLE-US-00001 (A): MIPA WBC Base Coat 000 72% of dry matter (Mipa SE, DE) Colouring components 28% of dry matter of which: turquoise interference pigment about. 85% by weight TiO.sub.2 on mica (Pyrisma ® T40-25 Color Space Turquoise SW (Merck KGaA); blue pigment Color Index P.B. 15:2 about 14% by weight blue pigment Color Index P.B. 15:4 about 1% by weight (B): MIPA WBC Base Coat 000 72% of dry matter Colouring components 28% of dry matter of which: blue interference pigment about 85% by weight TiO.sub.2 on mica (Pyrisma ® T40-23 Color Space Blue SW Merck KGaA); blue pigment Color Index P.B. 15:2 about 14% by weight blue pigment Color Index P.B. 15:4 about 1% by weight (C): MIPA WBC Base Coat 000 72% of dry matter Colouring components 28% of dry matter of which: red interference pigment about 85% by weight TiO.sub.2 on mica (Pyrisma ® T40-21 Color Space Red SW Merck KGaA); blue pigment Color Index P.B. 15:2 about 14% by weight blue pigment Color Index P.B. 15:4 about 1% by weight The absorption pigments are employed in the form of commercially available pigment concentrates

[0079] The coloured paints are in each case applied to black/white-painted test panels (Metopac T21G; Leneta) in a dry layer thickness of about 14 μm with the aid of a spray device and allowed to solidify. The colour separation ΔE* is measured using a BYKMac i colour measurement instrument in SMC5 mode without measurement stage. In each case, the L*,a*,b* values are measured at an angle of incidence of 45° and a viewing angle of 75°, and the colour separation of the coating over the white background and over the black background is determined for each paint composition.

[0080] The colour separation ΔE* for paint composition (A) is 16,

[0081] the colour separation ΔE* for paint composition (B) is 26 and

[0082] the colour separation ΔE* for paint composition (C) is 20.

EXAMPLE 2

[0083] The paint compositions prepared in Example 1 are in each case applied to the entire surface of transparent plastic plates (polycarbonate, Makrolon® UV, 3 mm thick) in a dry layer thickness of about 14 μm and allowed to solidify. As comparison, an uncoated plastic plate is used. The plastic plates are in each case fixed above a white cold-light lamp (about 5490 K) in such a way that the painted side faces away from the light source and forms the visible side. The light yield arriving on the visible side with the light source switched on is determined using a GL Spectis 5.0 Touch optical spectrometer (GL Optic Lichtmesstechnik GmbH, DE).

[0084] The photometric irradiation strength in the wavelength range from 200 to 1050 nm is about 800 lux (lx) for paint composition (A), about 590 lx for paint composition (B) and about 930 lx for paint composition (C). The photometric irradiation strength for the uncoated plastic plate is about 13500 lx.

[0085] For paint composition (A), a residual irradiation strength (irradiation strength coated/irradiation strength uncoated *100, in %) of about 5.8% can be determined, compared with a residual irradiation strength of 100% for the uncoated plastic plate. A corresponding residual irradiation strength of about 4.3% arises for paint composition (B) and a residual irradiation strength of about 7% arises for paint composition (C).

EXAMPLE 3

[0086] Paint composition (A) is applied directly to the transparent surface of a blue-emitting OLED W1832 in a dry layer thickness of about 14 μm and allowed to solidify. As comparison, an uncoated blue-emitting OLED W1832 is used.

[0087] The turquoise interference pigment has the transmission, reflection and absorption behaviour depicted in FIG. 1. A transmission maximum is evident in the wavelength range from 420 to 460 nm.

[0088] The OLED W1832 used in Example 3 has the emission spectrum depicted in FIG. 2. An emission maximum is evident in the wavelength range from 450 to 480 nm.

[0089] The uncoated OLED has a photometric irradiation strength of about 52 lx. The OLED W1832 coated with paint composition (A) still achieves a photometric irradiation strength of about 15 lx, which corresponds to a residual irradiation strength of about 28%, compared with a residual irradiation strength of 100% for the uncoated OLED. In comparison with Example 2, a clearly higher percentage residual light yield in relation to the uncoated substrate arises if a light source is used whose emission maximum is in the same wavelength range as the transmission maximum of the interference pigment used in the coating.