Hardware - Laser printer Q

Author

Laser printer Q

Warfare

2003-10-08, 12:44 pm

I didn't know under which forum this question might fit, so let me try and ask here.

Using a multi-format laser printer which has 3 resolutions available:
150dpi, 300dpi, 600dpi. Each black/white dot takes one bit of storage. Assuming A4 is 8 x 11 inches the printer must contain the entire image in memory to ptint it, and it has 1.5MB of memory installed.

My question is what is the highest resolution I can use with a$ given 1.5MB of memory? and how many MB's are needed to print A4 at 600dpi?

Thanks in advance

azimuth40

2003-10-08, 5:29 pm

Actually it will depend a lot on what the image is and what format is used. If it is postscript then most of the image is really a program. If the image is pure raster then it will depend on how many drum passes are required. The drum is not the size of the paper therefore multiple images are written to it. The buffer required for the dots is only the size of the drum itself. Basically the amount of the photon (laser) blast area. This is further coupled with gray scaling and dot size. Most printers can now use variable dot size and that has an affect.

Every laser manufacturer uses different variables and it is mostly based on who's laser engine is in use and how much control is given to paper speed versus print quality.

Short of looking at a specific makers manual for a given printer there is no single hard and fast rule. Normally they will have a table somewhere comparing image buffer to resolution and page size.

In your example having so little memory I assume that it does not do postscript but there are still other printer languages not based on purely the number of dots. Lets work the numbers for a full raster image however. Take 1/4 inch all around away as non printable giving 7.5 x 10.5

7.5 x 600 = 4500 + 8 for control = 4508
10.5 x 4508 = 47334 / 8 = 5.9 Kilobytes for full black and white. Now if we say the printer supports 256 shades of gray then that bumps it right back up to 47.3 Kilobytes. Variable dot size and or anti-aliasing probably multiplies it by 8 again to 378 KB.

But that whole paragraph is speculation because it depends on the printer software, rather the printer captures a full color image and converts it to gray scale or if the device driver does it and how much of your printer memory is really reserved for image buffer. It is a mistake to assume all of it or even half of it. Again many many unknowns

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