Patent Application
20080019659
Now the preferred embodiments according to the present invention will be described in details with reference to the accompanying drawings.
As shown in
The photonic fibers can be single mode photonic fiber and /or multimode photonic fiber, which diameter is in a range of 0.01 to 3.0 mm, and more preferably, 0.025 mm to 1.0 mm. The fibers are made in silica or polymeric materials, such as PMMA (PolyMethylMethaAcrylate), PS (PolyStyrole), PC (PolyCarbonate), PEA (PolyEthylAcrylate), PEMA (PolyEthyMethaAcrylate), PMMA/PEMA (PolyMethyl/PolyMethylAcrylate), etc. These photonic fibers are convey a light flow from one of its end to the other end and get off the lateral light only in the locations we need.
The applied photonic fiber has excellent transmittance and workability. The wrapping fiber can be nature fiber, continuous filament, staple yarn, and fiber with optical gain materials, etc. The materials can be cotton, wool, silk, and flax, metal, and synthetic and manmade materials.
In the second step, the wrapping photonic fibers are woven by using loom, such as Jacquard, Dobby, and digital weaving machine controlled by computer or manipulated by hand. The embodiment of the photonic fabric 14 is shown in
In the third step, the various color (and /or no color) patterns are printed by screen printing. The other printing procedure can also be used, such as letterpress printing, screen printing, digital printing, etc. The butterfly pattern is shown in
During the third step, certain wavelength converting materials, such as dyes, polymers, semiconductors, and phosphors, and nano-particles are mixed with print paste, then coating in the surface of the photonic fabric. These materials can change the colour and improve luminescence intensity, scattering intensity, light self-amplification, and contrast.
Certain wavelength converting materials, such as dyes, polymers, semiconductors, and phosphors, can be excited by light at a certain wavelength and emit light at another wavelength. In the visible range, this conversion causes colour change. The fluorescent dyes/pigment can be lucifer yellow CH, Fura Red, POPO-3 iodide, BODIPY TMR-X, BO-PRO-3 iodide, Calcium Orange, SNARF-1 carboxylic acid. The laser dyes can be Coumarin, Stibene, Rhodaminic compounds (such as Coumarin 307, 480, and 540, Stipene 420, Rhodamine 590), conducting polymers (such as PPV, PPH), and inorganic laser crystal powder, etc.
In a dye solution with suspension of nano- or sub-micron sized dielectric particles, or a composite comprising a polymeric matrix, doped with optical gain materials, and randomly distributed nano- or sub-micron sized particles, an incident light will be scattered and the path length of the photons will be increased. This causes amplified spontaneous emission (ASE), where light amplification can be realized at the wavelength where the ASE occurs. The nano-particles can be Titania, Zinc Oxide, Zirconia, and nano metal particles (range from 10 nm to 100 nm).
It should be noticed that it have the similar effects to add the above mentioned materials inside the core of photonic fiber during the photonic fiber fabrication process. To improve the effect, these materials can also be mixed with chemical solvent during the chemical surface treatment of photonic fibers in the fourth step or print the materials again after the fourth step.
In fourth step, surface treatment, such as chemical treatment, laser treatment, and mechanical treatment have been made in the location with patterns to improve the lateral illumination. This treatment is controlled by computer and can be performed to the photonic fabric according to the various patterns and shade of color. The advantage of laser treatment is that side-emitting intensity and pattern are controllable. By control the laser energy and the exposure time, the leaking light from photonic fiber can be controlled. Chemical surface treatment can achieve well-proportioned side-emitting effects. However, it maybe damages the photonic fabric. So it is important to select suitable solvent and procedure. By screening different solvents, recipes, and procedures, we find that MEE+TiO2 nanoparticle treatment have more obvious side-emitting effect.
In fifth step, a coupler 6 between the bundles of photonic fibers' end and the light source (such as LEDs) is applied to improve the coupling efficiency. The typical structure of the coupler 6 is shown in
The refractive index of optic resin used is very close with that of PMMA core of photonic fiber and same with that of the LED cover. There is no air between the LED and the bundle of photonic fibers. So the light propagates into the fibers with minimal reflection losses at LED/air and air/fiber ends. The reflective film coated inside the plastic tube serves as cylindrical mirror which can limit the light beam inside the cylindrical mirror and decrease leakage loss. An important consideration in selecting suitable substance to fill the gap between the LED and the end of photonic fabrics is the reflective index, which should be as close as possible to the reflective index of the cover/cap of the LED and of core of the photonic fiber
The light sources can be LEDs with different wave lengths, lasers, and lamps, etc. The connector for coupling is made by plastic or metal materials according to the different design and application. The color and luminescence intensity can also be tuned by adapting various colour LEDs controlled by predetermined circuits. Constant current drive circuit for ultra-light LED and dynamic scanning display circuit for multiple LEDs can be adapted to have different luminescent effects. The PCBs (printed circuit boards) are designed as flexibility and miniaturization to easily integrate in the apparel, arts, furniture etc. The rechargeable batteries or AC-DC converters can be adapted as power supply for various light sources.
The possible applications are enormous in areas as diverse as art, fashion, entertainment, toys, as well as communication. In particular articles capable of being manufactured from these photonic fabric displays of the invention are:
| Number | Date | Country | |
|---|---|---|---|
| 60730036 | Oct 2005 | US |
