QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, Ernst Dinkla <E.Dinkla@c...> wrote:
> Roy Harrington wrote:
> 
> >--- In QuadtoneRIP@yahoogroups.com, Ernst Dinkla <E.Dinkla@c...> wrote:
> >  
> >
> >>>Not sure if it's a benefit or not.  A counter-argument is that you would have
> >>>less diversity of dropsizes.  I think that diversity of dropsizes is particularly
> >>>beneficial to eliminating banding.  Actually its most important to use drops
> >>>that are big enough to merge between lines when the density gets darker.
> >>>
> >>>Roy
> >>> 
> >>>
> >>>      
> >>>
> >>With some printers that have few nozzles per head it may be worth it. 
> >>    
> >>
> >
> >I can't see number of nozzles having any effect.  The only difference between
> >say the 2200 w/96 nozzles and R2400 w/180 nozzles is that the head is 
> >larger -- it does 1 inch swath instead of a .53 inch swath per pass.  The nozzles
> >are 1/180 inch separation in both cases.  It takes multiple passes to fill 
everything
> >in between.
> >
> >Roy
> >
> >  
> >
> The weaving of more heads certainly will help in smoother patterns. Less 
> nozzles per head can be compensated by more passes and with that speed 
> sacrifice but it doesn't compensate the weaving. I have not checked the 
> number of passes and the resolution possible on the cheapest Epsons like 
> the C86 but I do not expect that they are in the same quality class  the 
> 2200/2400 are in. So I suggest that having more heads for the same task 
> can be a sensible thing.
> 
> Ernst

I think you are assuming that weaving is a bit more magic than it really is.
On say the 2200 in one pass the head puts down a dot up to every 1/360 inch
horizontally and every 1/180 inch vertically.  (The nozzles are all vertically in
a line).  So to get 1440x720 dpi there must be 4 passes to fill in the full 1440dpi
horizontal times 4 to fill in the full 720dpi vertical.  Imagine that the paper is
divided into all these 4x4 grids.  Each pass of the head can fill just one square
of this 4x4 grid so there will be 16 passes needed in the area to fill it all in.   The
whole function of weaving is to ensure that a different nozzle is used for
each of the 16 squares in the 4x4 grid.  There's no way to use more than 16
nozzles to fill in a 4x4 grid.  The difference between 96 nozzles of the 2200
vs 180 nozzles of the R2400 is that you are working on 180 different 4x4
grids at the same time.  But within a single 4x4 its the same basic thing.

Conceptually it pretty simple, in practice its a bit of a nightmare of shuffling data.

Roy