Konica Minolta bizhub 420 - Manual (Page 220)

Setting Up the KONICA MINOLTA PS Driver (Windows) 6
IC-204 6-36
Clear Memory Per Page
By selecting the check box, printer memory of each page is cleared.
Compatibility
Select “Optimize For Speed” and other PostScript output types from the pull
down list.
Use Bitmap Smoothing
By selecting the check box, bitmap dots are smoothed.