Datapath Challenges in Emerging Printing Applications
Posted 9th November 2018 by Marcus Timson
When any kind of image is printed with a digital inkjet process there are a number of technical problems that must be solved in order for the process to be successful. From the ink, to the printhead, through the electronics to the mechanics of the print engine to the software that is running it. Whatever it is, it requires a datapath. And with the growing number of industrial applications, this inevitably means a bigger challenge and it is a challenge that Meteor’s innovative technology is rising to meet.
Meteor Inkjet’s head of research and development, Phil Duffy, explains the datapath and the challenges Meteor faces when building datapaths for inkjet printers deployed in ever-evolving and emerging printing applications.
What is Datapath?
A datapath is the common name for the series of buffers which stores image data between the application program and the printheads. Depending on the application, the datapath performs some or all of the following tasks:
• Rotates the image to match the print direction
• Breaks the image up into lanes for each printhead
• Handles stitching at the overlap between heads
• Re-orders pixels to match the nozzle layout of the head
• Maps pixel values to available grey-levels
• Precisely tracks the movement of the document transport
• Keeps track of multiple documents between a product-detect sensor and each printhead
• Sends pixel data to each printhead at precisely the right time
So each application has a different datapath? How difficult Is this?
Yes, as each application within the industrial sphere continues to grow, so too does demand. Customers demand higher performance and better quality, and the demands on the datapath have increased. Some applications print high-speed, fully-variable images and need lots of processing power and fast network hardware. Other applications print repeated images or sequences of images and the datapath can be designed to take advantage of this to reduce overall system cost.
How do you solve the problem new applications present?
Meteor has developed several different memory modes to address the demands of different applications which simplify operation and reduce system cost:
• FIFO mode: Datapath buffers are organised as a simple queue. Each image is printed in order, and once only. This mode is required to support fully-variable data.
• Preload mode: Images can be preloaded into memory, selected at print time and printed multiple times. This mode is ideal for short or long-run repeats.
• Mixed mode: Background images can be pre-loaded, and variable parts of the image can be sent to the FIFO memory. This mode can dramatically reduce the network bandwidth and computer processing power needed to support high-speed printing.
• Flash mode: A library of images can be preloaded into non-volatile (flash) memory on the print controller hardware. The library can contain many thousands of different images. A specific image can be selected at print time. This mode is useful when a series of images needs to be repeated – for example, ceramic tiles, wooden flooring etc.
Advanced datapath features:
Meteor datapaths have evolved over time and incorporate many advanced features designed to improve performance and reliability. These include:
• Automatic handling of zero-gap images. Most current heads use multiple nozzle rows and if the gap between documents is smaller than the head width, the head must print on two documents at the same time. The datapath includes dual image buffers designed to make this possible.
• Compensation for fixed or variable errors in document tracking caused by encoder errors, belt thickness variation etc.
• Independent tracking of two sets of documents on the same transport.
• Synchronising images to pre-printed or embossed substrates.
• Tracking queued documents by their ID and reporting back to the application software when they have been printed.
• Removing specified documents from the print queue prior to printing
For more information about datapaths contact Meteor Inkjet Ltd on: firstname.lastname@example.org or visit www.meteorinkjet.com