EP 2 474 404 A1
Print head, upgrade kit for a conventional inkjet printer, printer and method for printing optical structures
LUXeXcel Holdings BV
LUXeXcel is a start-up company based in The Netherlands that are developing the ability to print optical structures using existing ink jet printers. Although the patent application shows a printhead similar to a disposable HP cartridge, the company have published a corporate video on their web site showing the use of a Roland plotter. The inks used are solvent-based containing UV-curable materials, and are discussed in EP 2 412 767 A1.
This patent application describes a way of monitoring and controlling the fabrication of optical structures using ink jet. The printhead has a nozzle array 4, each side of which is a curing device 8, such as a UV-LED. Perpendicular to the LEDs are a laser source 7’ and a CCD sensor 7”.
On the right the print zone is shown in more detail. Drops 14 fired from the nozzles build up the image 2 with the curable ink. The way the drop spreads can be controlled by the time before pinning the drop with the UV-LEDs, coupled with the evaporation of the solvent. Once the structure is complete it can be finally UV-cured.
The surface contour of the material deposited can be measured with the laser and CCD by triangulation as shown by arrow 6. This enables the geometry of the material deposited to be continuously monitored and iterated until the desired structure is achieved.
The applications for this process are many and varied, ranging from billboards, posters, packaging, labels, lamps and shades, light directing devices and so on.