To understand the principles of HP Indigo printing is to appreciate why the process is so convenient and the printed image is of such high quality.
The HP printing engine performs its operations in the following order:
1. Electrostatic charging of the electrophotographic Photo Imaging Plate (PIP) which is mounted on the imaging cylinder
2. Exposure of the PIP by a canned array of laser iodes. These lasers are controlled by the raster image processor, which converts instructions from a digital file into 'on/off' instructio
ns for the lasers.
3. Image development performed by the Binary Ink Developer (BID) units
4. Transfer of the inked image to the blanket cylinder
5. Removal of any residual ink and electrical charge from the PIP
6. Heating of the inked image carried by the blanket
7. Transfer of the heated inked image to the substrate held by the impression cylinder
*the above operations are repeated for every color separation in the image.
HP ElectroInkHP ElectroInk, as used on all HP Indigo digital presses, is a liquid ink containing electrically charged ink particles, available in a wide range of colors. HP ElectroInk enables digital printing by controlling the location of print partciles electrically, as with other digital printing technologies, such as dry toner xerography. Only one formulation of HP ElectroInk is needed to print on any substrate the press can handle. This allows rapid switching between substrates without having to worry about changing ink.
Advantage over dry tonerUnlike dry toner xerography, HP ElectroInk uses particle sizes as small as one to two microns. The particle size used in dry toner xerography is limited, as particles that are too small can become airborne and uncontrollable. The higher printing speed, the larger the particles need to be. The advantage of small particle size in a liquid carrier is that it enables higher resolution, uniform gloss, sharp image edges and very thing image layers. The thin image layer closely follows the surface of the paper, resulting in a highly uniform finish, complementing that of the paper.
So, HP ElectroInk produces results to match those possible with conventional offset printing. Dry toner depends heavily on the electrostatic properties of paper and small changes in relative humidity in the environment can cause noticeable variables in print quality. The high fusing temperature required for xerography limits the choice of coated paper or plastic film that can be printed.
*To find out what substrates are compatible with the HP indigo visit
(www.hp.com/go/myhpindigoweb)
Here is how to use it:
*Access the website & log in
1. Select "print media"
2. Select the Media Locator
3. Specify your media requirements accordint to:
a. The HP Indigo digital press you use
b. The type of media on which you intend to print
c. Basis weight
d. Your location
Additional information about approved media, testing and certification of HP Indigo media can be found on RIT's website: www.printlab.rit.edu
