12/7/96


Hi Everybody,

Does somebody has heard something about an enhancement for laser printers

called LAZARPRINT and

abble to increase the resolution at 6800 DPI and 1024 Gray levels!!!(I know

it looks impossible)

I'm interresting by technical information and manufacturer.

Salutations.

Jacky Larnould

tel 33 (0)4 67 72 28 26

fax 33 (0)4 67 79 54 90

email larnould@mnet.fr


Dear Microscopists,

Impossible or not, this product really exists !!!

In addition to the high quality grayscale images, the speed of the process

is also remarkable: due to a direct access to the video port of the printer

via a special interface, a picture of letter size is transferred and printed

out within the time the laser printer needs for paper skip alone (+/- 10

seconds !).

The near photographic quality obtained at a very low cost (use of plain

paper) makes the LazarPrint system the ideal solution if you want to print

pictures obtained with really high resolution grabbing systems (eg our ORION

4.2 for Windows that gives you a resolution up to 4000 x 4000 pixels and 256

gray levels).

For more information, please contact:

I.C.I. sarl (France)

Voice: + 33 384 58 02 43

Fax: + 33 384 54 03 98

E.L.I. sprl (Belgium)

Voice: +32 2 726 31 02

Fax: +32 2 726 08 65

Email: orion @infoboard.be

Best regards,

Paul Vanderlinden.

Sales Manager.

See our web site: http://www.microscopy-uk.org.uk

To contact us:

E.L.I. sprl

Technical support:

Jean-Louis Leclef: Phone: +32 67 21 25 07

Fax : +32 67 22 09 53

Email: jleclef@hypercon.com

Sales support:

Paul Vanderlinden: Phone: +32 2 726 31 02 (NEW N° !!!)

Fax : +32 2 726 08 65

Email: orion@infoboard.be


Chere Jacky:

The little gizmoes which make a low DPI printet think it's a high DPI

printer ARE A RIP OFF. They are fiddling the system and really don't

give you any real additional information. Contact John Mackenzie at

<supervisor@emc.ncsu.edu> who is the expert on these matters.

Patrick Echlin

pe13@cus.cam.ac.uk


Society : LEUTRON VISION GmbH

D-82216 Gernlinden (Germany)

FAX : (0 81 42) 4 02 19


>We use the LazarPrint print board in a HP 4+ laser printer. The board

allows the printer to print at 4800 dpi. We purchased ours from Smart

Analytical Products in Maryland, USA. However, the board is made in

Germany, and I am do know who markets the board in Europe. The board is

very fast. You can even print out multiple copies of 20MB+ image files in

the same manner you would print a text file. The normal output of the

laserjet produces a dot pattern that is easily seen if you examine a print

with a magnifying glass. If you look at the grain stucture of a picture

printed using the LazarPrint board, the dots are almost too small too seen.

Each pixel can accept 1024 gray levels, but only 256 of these will be

printed. However, this allows a great deal of contrast manipulation. The

board does an excellent job with electron micrographs. I have no commercial

interest in the board.

Regards,

John J. Turek, Ph.D.

Purdue University

Dept. of Basic Medical Sciences

Core Laboratory for Image Analysis

and Multidimensional Applications (CRISTAL)

phone: 317-494-5854

fax: 317-494-0781

email: jjt@vet.purdue.edu


Patrick, understanding some of the principles of LaserJet printing may help to draw some more objective conclusions:

LaserJets like many other printers print in lines (lpi). The lines represent in digital image printing lines of pixels. If the pixels are printed squarely than each square area (of a width equal to that of the actual line width) must be printed with a desired amount of ink variations in order to generate the gray levels (see John Russ' book for a nice illustration on how this is done in a LaserJet). LaserJets and inkjets use dots as the smallest printed entity. If you would print with 600 dpi and 100 lpi (LaserJet 4) than you could place 6 dots per line (600/100=6), As a consequence you can maximally place 6x6 dots per pixel or make 36 gray levels plus no-dots (white). Thus a LaserJet 4M will print with 37 gray levels. This is just at the limit of gray level recognition. A 1200 dpi printer which uses 100 lpi, will be able to generate 145 gray levels per pixel (1200/100 = 12; 12x12+1=145). That's why the Lexmark is so good because the eye can't distinguish that amount of gray levels (beyond the contrast resolution of our eyes). However, 100 lpi (25:100= 0.25 mm) also is just at the recognition level of the eye with regards to spatial resolution. Print heads in LaserJets can print much better and ,if combined with HP's superfine ink powders, they can easily be driven at 4800 dpi on plain paper. There are many high-resolution printers on the market which do better. However, for comparison, print speed is as important as adequate print resolution. LazarPrint prints 300 lines per inch (lpi) and 256 gray levels, both surely beyond the resolution limit of the unaided eye and thus producing "photography like" printing quality. However, in addition, LazarPrint prints 1- 10 MB of images per page in 20 sec. (on a conventional LaserJet).

If you like to see some proof, look at a comparison of these printers at the following web site, where dpi/lpi/eye resolution are compared for a 1Kx1Kx8-bit test image:

http://panda.uchc.edu/htklaus/DigiLab/Printing-ResultsL.html

Patrick, trust physics and experimental proof not emotions. I don't like gizmos either, that's why I took the time and compared the actual print quality. Than, I made up my mind and for now over two years I never used my photolab again, but I printed over 20,000 images (pages with up to 8 images each) on my LaserJet, submitted MSA and other abstracts, made all my slides and published papers; all with the help of my old but good LaserJet.

Address of LazarPrint developer: bm484646@muenchen.org (Mikel Jaeth)

I am commercially not involved in any of the mentioned resources. Best season greetings Klaus

Klaus-Ruediger Peters

Peters@BSAC.UCHC.EDU


Dear Klaus: Thank you for your patient explanation of Laser Jet

printing. We tried these gizmo's about two years ago and at that time

could see no improvement. We now use a 600dpi pinter of a clay covered

brilliant white paper using superfine print powder and are satisfied

with the results. Perhaps things have changed in the past two years.

Sincereley

pe13@cus.cam.ac.ukPatrick


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