Curved Optical Elements for Non-Diffractive 3D Effects
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Solution Overview
Problem
Existing optically variable devices (OVDs) have limited ranges of non-diffractive three-dimensional optical effects, making them susceptible to counterfeiting and simulation, necessitating the development of more secure and discernible optical features.
Innovation Solution
The OVD employs recessed and curved optical elements with controlled cross-sectional profiles and micro-patterned surfaces to create multiple point images visible within specific angles of elevation and rotation, preventing diffractive effects and enhancing security through varied optical effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If simple geometric shapes (straight angled or semi-circular) are used for optical elements, then the device structure is simple and easy to manufacture, but the range of optical effects is limited and easier to counterfeit
Solution Approach 1:
The patent employs optical elements with curved cross-sectional profiles including semi-circular, parabolic, elliptical, and asymmetric curved shapes. These curved geometries focus incident light to create non-diffractive three-dimensional point images that appear suspended in space, providing diverse and complex optical effects that are difficult to counterfeit while remaining manufacturable through conventional molding or embossing techniques.
2Reliability
If diverse and complex optical effects are introduced to prevent counterfeiting, then security level increases, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies different cross-sectional profiles to different optical elements within the same device. Each optical element can have a customized curve (semi-circular, parabolic, elliptical, or asymmetric) tailored to produce specific point image characteristics. This local differentiation allows the device to exhibit multiple distinct optical effects simultaneously, enhancing security while maintaining a relatively simple overall structure that is easy to manufacture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides strong, stable, and easily discernible non-diffractive three-dimensional optical effects, making it difficult for counterfeiters to duplicate, thereby increasing the security of the device.
Implementation Method 1
The substrate includes stereo pairs of elements formed on the substrate that reflect or refract light to a focal point that is spaced apart from the surface of the substrate
Implementation Method 2
The substrate includes stereo pairs of elements formed on the substrate that reflect or refract light to a focal point that is spaced apart from the surface of the substrate
Implementation Method 3
stereo pairs of elements formed on the substrate that reflect or refract light to a focal point that is spaced apart from the surface of the substrate. This creates a point image at the focal point that is visible to a viewer
Data Source
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AI summary
An optically variable device includes a substrate and a plurality of optical elements formed in or on the substrate and being structured to provide a three- dimensional optical effect for a viewer when light is incident on the optical elements. The plurality of optical elements are arranged as a plurality of stereo pairs structured to reflect or refract Sight to corresponding focal points in three-dimensional space apart from the optically variable device to form the three-dimensional optical effect. The optical elements include one or more optical elements that are curved structures having a curvature that is either less than or greater than a semi-circle.