摘要:
The light transmitted and reflected by all-dielectric optically variable pigments varies according to viewing angle. The color travel of an all-dielectric optically variable pigment depends on amplitude changes and wavelength shifts in reflectance peaks of the pigment. The width and center wavelength of reflectance peaks can be controlled by selecting the ratio of thicknesses between high-index and low-index layers in a thin film stack. Reflectance peaks can regenerate or become suppressed and shift with tilt angle, thus providing a wide variety of color trajectories.
摘要:
The invention relates to anisotropic, reflective, magnetic flakes. In a liquid carrier and under influence of an external magnetic field, the flakes attract to one another side-by-side and form ribbons which provide higher reflectivity to a coating and may be used as a security feature for authentication of an object.
摘要:
The invention relates to anisotropic, reflective, magnetic flakes. In a liquid carrier and under influence of an external magnetic field, the flakes attract to one another side-by-side and form ribbons which provide higher reflectivity to a coating and may be used as a security feature for authentication of an object.
摘要:
All-dielectric diffractive pigment flakes can be applied to an object to impart a diffractive effect to the object without substantially changing the background color of the object. In one case, such diffractive pigment flakes can be applied to a white object to impart a white diffractive effect. The thickness of the dielectric layers in the diffractive pigment flakes can be chosen to provide thin-film interference, as well as diffraction from the interfaces between layers patterned with a diffraction grating. In some cases, the thin-film interference can provide color shifting in addition to the diffractive effect.
摘要:
An optical structure includes a light transmissive substrate having a surface relief pattern applied thereon, such as a hologram. One or more layers can be patterned corresponding to materials playing the role of absorbers or reflectors on a Fabry-Perot type of optical structure. These materials are applied over portions of the surface relief pattern so as to form alphanumeric characters, bars codes, or pictorial or graphical designs. Additional layers may be applied to the patterned layer of the reflective or absorber materials and exposed portions of the surface relief pattern in order to provide desirable optical effects to the exposed portions of the surface relief pattern. In some embodiments, the optically active coating is a color shifting thin film, or contains color shifting flakes based on Fabry Perot designs.
摘要:
A printed image is disclosed wherein the image may be in the form of an array of magnetically aligned platelets or flakes that may by uniform in shape and size and wherein the flakes are arranged in a particularly manner to form optically illusive images useful as security devices, or useful in beam steering applications. In one embodiment of this invention printed array is disclosed a plurality of concentric rings of magnetically aligned platelets disposed upon a substrate in the form of a Fresnel structure, preferably a Fresnel reflector. Advantageously, since the magnetic field can be controlled with respect to strength and direction, one can easily design a field that will correct for spherical aberration that would otherwise be present in a typical Fresnel reflector. In other embodiments of the invention optically illusive images of funnels, domes and cones are printed.
摘要:
The instant invention provides an asymmetrical orientable flake for use in a carrier. The flake includes a metal reflector layer and a coating of a carrier-repellent material coated on a single side of the flake, for orienting the flake in the carrier so that the flake rests upon the carrier having a first side at least partially out of the carrier and a second side immersed in the carrier. The flake has an asymmetrical feature, such as a color shifting coating on a single surface of the reflector layer. Alternatively, the asymmetrical feature is either a relief symbol or an asymmetrical profile of the flake.
摘要:
A method of forming pigment flakes includes using a deposition substrate having a plurality of regions; some of the regions are raised or lowered so that there is a level difference between each two adjacent regions. A coating deposited onto this substrate breaks along region borders when it is separated from the substrate. In one embodiment, the substrate includes first and second regions, wherein each of the first regions is in an abutting relationship with at least one of the second regions. All the first regions are at a first level and all the second regions are at a second level, and the difference between the first and second levels is greater than a predetermined value. The first and second regions are preferably square-shaped regions for manufacturing square flakes with practically no debris.
摘要:
Diffractive pigment flakes are selectively aligned to form an image. In one embodiment, flakes having a magnetic layer are shaped to facilitate alignment in a magnetic field. In another embodiment, the flakes include a magnetically discontinuous layer. In a particular embodiment, deposition of nickel on a diffraction grating pattern produces magnetic needles along the grating pattern that allow magnetic alignment of the resulting diffractive pigment flakes. Color scans of test samples of magnetically aligned flakes show high differentiation between illumination parallel and perpendicular to the direction of alignment of the magnetic diffractive pigment flakes.
摘要:
The present invention provides a magnetic multilayer pigment flake and a magnetic coating composition that are relatively safe for human health and the environment. The pigment flake includes one or more magnetic layers of a magnetic alloy having a substantially nickel-free composition including about 40 wt % to about 90 wt % iron, about 10 wt % to about 50 wt % chromium, and about 0 wt % to about 30 wt % aluminum. The coating composition includes a plurality of the pigment flakes disposed in a binder medium.