Ink supply unit for an ink jet printer

#The present invention relates to an ink jet printhead assembly with an ink distribution manifold

#Many different types of printing have been invented, a large number of which are presently in use. The known forms of printers have a variety of methods for marking the print media with a relevant marking media. Commonly used forms of printing include offset printing, laser printing and copying devices, dot matrix type impact printers, thermal paper printers, film recorders, thermal wax printers, dye sublimation printers and inkjet printers both of the drop on demand and continuous flow type. Each type of printer has its own advantages and problems when considering cost, speed, quality, reliability, simplicity of construction and operation etc.

#In recent years, the field of inkjet printing, wherein each individual pixel of ink is derived from one or more ink nozzles has become increasingly popular primarily due to its inexpensive and versatile nature.

#Notwithstanding any other forms which may fall win the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

#FIG. 1 illustrates schematically a single ink jet nozzle in a quiescent position;

#FIG. 2 illustrates schematically a single ink jet nozzle in a firing position;

#The preferred embodiment is a 1600 dpi modular monolithic print head suitable for incorporation into a wide variety of page width printers and in print-on-demand camera systems. The print head is fabricated by means of Micro-Electro-Mechanical-Systems (MEMS) technology, which refers to mechanical systems built on the micron scale, usually using technologies developed for integrated circuit fabrication.

#As more than 50,000 nozzles are required for a 1600 dpi A4 photographic quality page width printer, integration of the drive electronics on the same chip as the print head is essential to achieve low cost. Integration allows the number of external connections to the print head to be reduced from around 50,000 to around 100. To provide the drive electronics, the preferred embodiment integrates CMOS logic and drive transistors on the same wafer as the MEMS nozzles. MEMS has several major advantages over other manufacturing techniques:

#mechanical devices can be built with dimensions and accuracy on the micron scale;