Invention Grant
- Patent Title: Optically variable security device
- Patent Title (中): 光学可变安全设备
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Application No.: US12087513Application Date: 2007-01-19
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Publication No.: US08211596B2Publication Date: 2012-07-03
- Inventor: Brian William Holmes
- Applicant: Brian William Holmes
- Applicant Address: GB Basingstoke
- Assignee: De La Rue International Ltd.
- Current Assignee: De La Rue International Ltd.
- Current Assignee Address: GB Basingstoke
- Priority: GB0601093.8 20060119
- International Application: PCT/GB2007/000176 WO 20070119
- International Announcement: WO2007/083140 WO 20070726
- Main IPC: G03F7/00
- IPC: G03F7/00
Abstract:
A method of forming a security device comprises: a) providing an undeveloped photoresist layer on an electrically conductive layer; b) forming a first diffractive pattern in the undeveloped photoresist layer using optical-interferometry; c) forming a second diffractive pattern in the undeveloped photoresist layer using electron beam lithography; and d) thereafter developing the photoresist layer.
Public/Granted literature
- US20090004571A1 Optically Variable Security Device Public/Granted day:2009-01-01
Information query
