Authenticating and anti-counterfeiting device for currency
First Claim
Patent Images
1. A flexible, paper-like document of value comprising:
- an integral flexible thin-film nematic liquid crystal device which undergoes a visible change in response to an applied voltage; and
an integral flexible thin-film photovoltaic material electrically coupled to said liquid crystal device and responsive to ambient or artificial light to produce said applied voltage, whereby said document is easily authenticatable by the man-in-the-street and also is unreproducible by reprographic apparatus.
1 Assignment
0 Petitions
Accused Products
Abstract
Currency or other documents or items of value containing a liquid crystal/photovoltaic device which produces a coded display in response to artificial or ambient light. Such a device functions both as an anti-counterfeiting deterrent and also as a means for permitting the man-in-the-street easily to authenticate the validity of a document containing such a device.
-
Citations
18 Claims
-
1. A flexible, paper-like document of value comprising:
-
an integral flexible thin-film nematic liquid crystal device which undergoes a visible change in response to an applied voltage; and an integral flexible thin-film photovoltaic material electrically coupled to said liquid crystal device and responsive to ambient or artificial light to produce said applied voltage, whereby said document is easily authenticatable by the man-in-the-street and also is unreproducible by reprographic apparatus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 18)
-
- 12. A method of making a flexible paper-like security document comprising the step of incorporating in the document a flexible thin film liquid crystal/photovoltaic device which produces a visible code only when the document is exposed to ambient or artificial light.
-
16. A method of making a thin flexible paper-like security document easily authenticatable and also non-counterfeitable by copying apparatus of the type which exposes a document to light, comprising:
-
forming a light-transparent area in a surface of the document; placing a flexible thin-film photovoltaic material within the document and in light communication with the transparent area; placing within the document and in light communication with the transparent area a flexible thin-film nematic liquid crystal device which displays an human-observable predetermined image only when electrically energized; and electrically interconnecting within the document said photovoltaic material and said liquid crystal device so that when an authentic document is exposed to ambient light, said photovoltaic material electrically energizes said liquid crystal device to alter an optical characteristic of said predetermined image, and so that when the document is exposed to the brighter light in a copying apparatus, said photovoltaic material electrically energizes said liquid crystal device to cause the resulting copy of the document to have permanently formed thereon a visible reproduction of said predetermined image but of a different said optical characteristic. - View Dependent Claims (17)
-
Specification