Printing of liquid crystal droplet laser resonators on a wet polymer solution and product made therewith

Patent metadata

Field	Value
Publication number	US-9720173-B2
Application number	US-201615266135-A
Country	US
Kind code	B2
Filing date	Sep 15, 2016
Priority date	May 25, 2012
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A method of manufacturing a security feature for identifying objects or documents of value. The method may include the steps of encoding information in a pattern; and ink jet printing a chiral nematic liquid crystal material from a reservoir using a print head on to a substrate in the pattern. Thus, the method forms a patterned array of chiral nematic liquid crystal material deposits. The print head, or the reservoir, or both, may be heated to a temperature above the clearing point of the chiral nematic liquid crystal material. The chiral axes of the chiral nematic liquid crystal material deposits may be aligned substantially perpendicular to the substrate such that a predetermined portion of the electromagnetic spectrum is selectively reflected over other regions of the electromagnetic spectrum by the chiral nematic liquid crystal material deposits.

First claim

The invention claimed is:

1. A method of manufacturing a security feature for identifying objects or documents of value, the method comprising:
encoding information in a pattern; and
ink jet printing a chiral nematic liquid crystal material from a reservoir using a print head on to a substrate in the pattern to form a patterned array of chiral nematic liquid crystal material deposits, wherein the print head, or the reservoir, or both, is heated to a temperature above the clearing point of the chiral nematic liquid crystal material, and wherein the chiral axes of the chiral nematic liquid crystal material deposits are aligned substantially perpendicular to the substrate such that a predetermined portion of the electromagnetic spectrum is selectively reflected over other regions of the electromagnetic spectrum by the chiral nematic liquid crystal material deposits.

2. The method according to claim 1 , wherein the pattern is a two-dimensional pattern.

3. The method according to claim 1 , wherein the print head is heated to a temperature above the clearing point of the chiral nematic liquid crystal material.

4. The method according to claim 1 , wherein the reservoir is heated to a temperature above the clearing point of the chiral nematic liquid crystal material.

5. The method according to claim 1 , wherein the print head and the reservoir are heated to a temperature above the clearing point of the chiral nematic liquid crystal material.

6. The method according to claim 1 , wherein the predetermined portion of the spectrum is selected to reflect a known portion of the spectrum created by a device equipped with an LED light source where otherwise the material possesses only low visibility to the unaided eye.

7. The method according to claim 1 , wherein the chiral nematic liquid crystal material includes a fluorescence dye, a fluorescent laser dye, a quantum dot, or other light harvester or gain additives.

Assignees

• Johnson Matthey Plc

Inventors

• Coles Harry
• Hutchings Ian
• Gardiner Damian
• Hsiao Wen-Kai
• Hands Philip
• Morris Stephen
• Wilkinson Timothy

Classifications

• G02B6/1225 Primary

  comprising photonic band-gap structures or photonic lattices · CPC title

• G02F2202/36

  Micro- or nanomaterials · CPC title

• H01S3/094076

  Pulsed or modulated pumping (H01S3/1024 takes precedence) · CPC title

• H01S3/094034 Primary

  the pumped medium being a dye · CPC title

• H01S3/1686

  Liquid crystal active layer · CPC title