Patent US1126028A successfully refreshed from Google Patents.
Patent EP0328320A1 successfully refreshed from Google Patents.
EP0328320A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Security device
Assignee: Akzo Nobel UK PLC
•
Filing: 1989-02-03
•
Granted: —
•
Expires: 2009-02-03
Abstract
Abstract One or more threads of a photochromic yarn are used as a security device in woven material, for example a label (1). The threads are substantially colourless when irradiated with visible light but are reversibly converted to a coloured state (2) when irradiated with ultraviolet light.
Inventors
- 👤 Peter Wright
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 14:47
CPC Classifications
G; G09; G09F; G09F3/00; G09F3/02; G09F3/0291; G09F3/0294; D; D06; D06H; D06H1/00; D06Q; D06Q1/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
36 words
A security device comprising woven material containing one or more threads of photochromic yarn, the yarn being substantially colourless when irradiated with visible light and reversibly converting to a coloured state when irradiated with UV light.
Claim 2
Dependent Claim
36 words
A security device comprising woven material containing one or more threads of photochromic yarn, the yarn being substantially colourless when irradiated with visible light and reversibly converting to a coloured state when irradiated with UV light.
Claim 3
Dependent Claim
16 words
A security device as claimed in claim 1, which is in the form of a label.
Claim 4
Dependent Claim
20 words
A security device as claimed in claim 1 or 2, wherein the photochromic yarn is woven into the woven material.
Claim 5
Dependent Claim
23 words
A security device as claimed in any preceding claim, wherein the device comprises one thread of photochromic yarn incorporated in the woven material.
Claim 6
Dependent Claim
22 words
A security device as claimed in any preceding claim, wherein the photochromic yarn comprises cellulose acetate fibre having photochromic compound incorporated therein.
Claim 7
Dependent Claim
18 words
A security device as claimed in claim 5, wherein the photochromic compound is a spiropyran or a spiro-oxazine.
Claim 8
Dependent Claim
17 words
A security device as claimed in claim 5, wherein the photochromic compound is a fulgide or fulgimide.
Claim 9
Dependent Claim
39 words
The use of one or more threads of photochromic yarn as a security device in woven material, the yarn being substantially colourless when irradiated with visible light and reversibly converting to a coloured state when irradiated with UV light.
Claim 10
Dependent Claim
39 words
The use of one or more threads of photochromic yarn as a security device in woven material, the yarn being substantially colourless when irradiated with visible light and reversibly converting to a coloured state when irradiated with UV light.
Claim 11
Dependent Claim
14 words
The use as claimed in claim 8, wherein the woven material is a label.
Claim 12
Dependent Claim
28 words
The use as claimed in claim 8, wherein the woven material is a textile piece good and a thread of photochromic yarn is woven into an edge thereof.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.