mark@intek01.UUCP (Mark McWiggins) (07/25/90)
We currently have a Laserjet II. The output from it looks fine on the original, but when photocopied is comes out fuzzy around the edges. A local printshop has a 600 dpi Postscript printer, so we've had to use that for critical stuff. I've read that the Laserjet III does sneaky enough things with its dot placement such that the output looks remarkably better. If we got one, could we expect to dispense with trips down the street to the 600 dpi printer? Thanks in advance for any insight. -- Mark McWiggins Integration Technologies, Inc. (Intek) +1 206 455 9935 DISCLAIMER: I could be wrong ... 1400 112th Ave SE #202 Bellevue WA 98004 uunet!intek01!mark Ask me about C++!
scapri@HPDMD48.BOI.HP.COM (Sandra Capri) (08/20/90)
>/ hpdmd48:comp.laser-printers / mark@intek01.UUCP (Mark McWiggins) / 11:36 am Jul 24, 1990 / >I've read that the Laserjet III does sneaky enough things with its dot >placement such that the output looks remarkably better. In response to your query on the LaserJet III, I am posting an excerpt from an HP brochure. To keep this posting fairly short, I omitted much information about RET, including the Technical Overview. I will be glad to email the entire text to anyone who requests it. It contains much more information about RET and the LaserJet III in general. sandra_capri%hpdmd48@hplabs.hp.com or sandra_capri@hpdmd48.boi.hp.com or hplabs!hpbsl249!sandra_capri (excerpt follows, typos are mine) Resolution Enhancement Technology --------------------------------- Resolution Enhancement technology improves edge smoothness and prints sharper points and line intersections by intelligently adjusting dot size and position in relationship to neighboring dots. This process is designed to enhance the print quality of both text and graphics without affecting gray-scale images. Dot position is adjusted in the horizontal plane by controlling the on-off timing of the laser beam. This process is used to smooth the jaggies of nearly vertical lines. Dot size is controlled by varying the intensity of the laser beam. This process is used to smooth nearly horizontal lines and to create sharper points and line intersections. Nearly Vertical Lines and Curves -------------------------------- The HP LaserJet III printer's laser beam scans the photosensitive drum from right to left. This makes it possible to shift the dot placement on the grid to the left or right by adjusting the on-off timing of the laser beam; the beam is turned on either sooner or later. The resulting edge of a nearly vertical line or curve looks smoother because the dot's position has been shifted closer to neighboring dots. Nearly Horizontal Lines and Curves ---------------------------------- Smoothing nearly horizontal lines and curves is technically more complicated than the process described for vertical enhancements. Horizontal smoothing is achieved by varying dot size. Resolution Enhancement modulates the intensity of the laser beam to address the problem. This deposits smaller than normal amounts of energy on the photosensitive drum. The drum, in turn, attracts a smaller amount of toner and produces smaller dots. Resolution Enhancement precisely controls the size of a printed dot by modulating the laser beam. Its smoothing effect is created by placing dots that have been divided in 20 percent increments into corollary relationships. The 20 percent dot is placed opposite the 80 percent dot, the 40 percent dot opposite the 60 percent dot and so on to create a line that appears uniform in width.