Printer Technology

The world's fastest printers run at several hundred feet per minute (fpm) using a continuous web and they occupy the space of 3 large bedrooms1. They have a typical resolution of 2,400 dpi. However, they can't operate on variable data and are economic only for large runs, typically at least tens of thousands of pages. The fastest variable printers2use sheet media, have an equivalent speed of around 25 fpm, and are typically limited in resolution to 600 dpi. Why is the speed for variable printing around 20 times slower and the resolution substantially less? Because the traditional architecture of electro-photographic printing machines uses modulated laser beams to form the image.


New printing technology may enable the speed and resolution of gravure printing with the variable data capability of laser printing, provided in a small footprint with low cost of ownership.

 

Salmon Technologies, see below, has invented a new method of printing, Solid State Printing, that does not require any lasers or photoelectric drums. The image is digitally formed by direct writing, using 40-volt amplitude control signals applied to imaging electrodes.

Challenges met so far with Solid State Printing

  • Digital imaging capability has been demonstrated at a web speed of 200fpm (and arbitrary print width)
  • Polymerized toners (chemical toners) are available and have been tested
  • Surface treatments having good tribo properties have been developed3
  • Large format glass substrates have been patterned to form writing heads
  • Custom ASIC capability for imaging drivers has been demonstrated

Challenges remaining

  • Good image transfer from the writing head to a roller or belt at high speed, primarily enabled by a precise gap4between them
  • Potential durability issues relating to toner that may be recycled through the printer multiple times5

It is currently possible to create a printer having extraordinary capabilities and low cost of ownership. It can have the quality and speed of gravure while processing variable data. The printing device will be much more compact than existing machines, and may have much improved reliability.

 

6,309,049 Issued Printing Apparatus and Method for Imaging Charged Toner Particles Using Direct Writing Methods

This patent provides broad coverage in 33 claims for direct writing methods using dry toner. Both additive and subtractive imaging methods are described. Toner conveyors are channelized, with one conveyor for each pixel site on the print receiving medium. The technology of the writing head can be implemented using available thin film processes on glass substrates. Applying the printing technology to a toner cartridge is also claimed.

Sister Company

The printer technology patents are held by a sister company, Salmon Technologies, LLC, based in San Luis Obispo, California. Salmon Technologies welcomes enquiries from companies interested in working with us to develop this technology.

  • 1See for example the gravure printer, JSASY-PLC series, at a print speed of 492 fpm and volume of 5,854 cubic feet.
  • 2Xerox iGen4 at 110 ppm and Kodak NexPress S3000 at 100 ppm.
  • 3Since the preferred transport mode involves rolling and sliding of toner particles on the writing head surface, a tribo-neutral coating is desirable. This problem was solved by making the working surface look to a toner particle like another toner particle. The working surface "particle" has infinite radius, but also includes flow control and charge control agents in the same amounts as the toner particles.
  • 4Image quality depends directly on having a small and consistent gap. Run out error in the first transfer roll can make this difficult; to overcome this, a proprietary lapping technique is proposed.
  • 5Spherical toner particles formed by polymerization are intrinsically rugged. However, fine surface agents may become embedded while the toner is worked, and this may lead to variations in tribo-properties.

Issued Patent

6,309,049 Printing apparatus and method for imaging charged toner particles using direct writing methods

Published Patent

20080036842 Electronic printing press

Publication

Solid State Printing: A New High-Speed Printing Technology, authored by Peter C. Salmon and Editor Anne Priede, The Hard Copy Observer, Lyra Research, Boston, Massachusetts, January, 2009.