Xerox 721P83071 manual Interpolation and scanned images, Switching paper size and feed modes

PRODUCT DIFFERENCES/USER CONSIDERATIONS

Note: On 4635MX systems, Print Darkness is restricted to only level 5 when printing in the MICR mode.

Interpolation and scanned images

The 4635 LPS accepts 300 spi data and prints it using a 600 spi dual beam raster output scanner (ROS). To convert 300 spi input data to 600 spi print output, the system uses an interpolation algorithm to smooth lines and improve the quality of 300 spi fonts and line art.

Note that the interpolator does not always improve scanned half- tone images. The Xerox 7650 Pro Imager Scanner has several screens which attempt to maximize the effect of interpolation on the quality of half-tones. However, in order to utilize these new screens you must re-scan previously scanned images. The relative level of improvement needs to be evaluated by you on your own half-tone images.

Switching paper size and feed modes

The 4635 LPS system operates in a multiple-pitch print mode: 7 pitch to 3 pitch.

The multi-pitch feature allows your 4635 LPS to adjust the pitch mode according to the width of the paper you are using. Table 5-2 shows the relation between the pitch mode, the maximum width of the paper being fed in a long edge feed mode, and the page per minute (PPM) rate. Long edge feed mode means the sheet is fed into the paper path with its long edge first.

Table 5-13.	Pitch modes
Pitch mode		Maximum paper width	PPM rate
3-pitch		17 inches/431 mm	58 PPM
4-pitch		15.3 inches/389 mm	78 PPM
5-pitch		12.1 inches/308 mm	98 PPM
6-pitch		10.2 inches/259 mm	117 PPM
7-pitch		9 inches/229 mm	135 PPM
8-pitch*		7.4 inches/188 mm	154 PPM

*8 pitch is enabled only with the optional Paper Feeding Enhancement Kit installed

For papers whose widths range from 8.66 to 9 inches, the 4635 prints with slightly reduced productivity at 135 pages per minute, with seven-page images per photoreceptor revolution. Productivity is slightly reduced because in order to maintain print speed for papers of this size, the system must temporarily suspend xerographic print quality checks. The 4635 maintains the highest print quality by periodically reducing printer output to perform xerographic print quality checks. After a print quality check, the system automatically resumes printing at full productivity.

XEROX 4635 LASER PRINTING SYSTEM PRODUCT REFERENCE 5-23