HowTo: pick best alignment value?

[l_d_allan]

When doing an alignment check on my Canon 9000-2, it prints a column for each of the eight colors. For each color, there are 11 choices, from -3 to +7. The directions indicate to "pick the best" for each color.

[Edit] The actual message that shows up from the 9000-2 print driver is:

Execute print head alignment. Examine the printed patterns, and enter the
pattern number of the pattern with the least noticeable streaks in the fields
for columns A to H.

I'm unclear what criteria to use for "least noticeable streaks". Some of the rectangles are pretty much solid, while others have distinct vertical lines (about 30 or so). Others have some of the vertical lines being somewhat wavy.

My speculation is that you pick the value for each color that has the most distinct vertical lines, but I wanted to check with the forum experts.

Also, would it be best to use glossy photo paper for this alignment rather than plain paper, for more sharpness to pick from?

 

[ghwellsjr]

You got it backwards. You want to pick the one that is the most solid, with the least amount of lines.

It shouldn't matter what kind of paper you use although if it is easier to see the difference between solid blocks and lined blocks using photo paper, then you can use that.

The purpose of alignment is to make the nozzles that are used in each direction of the print head lay down their drops on the same spot. The nozzles are aimmed backwards from the direction of travel so that the droplets have no horizontal motion as they travel down from the print head to the paper.

Why don't you try two alignment checks with your thinnest paper and your thickest paper and see if it make a difference?

 

[The Hat]

l_d_allan
If you have to do a head alignment and your not sure what youre doing then let the printer do it for you automatically.
Just go to custom Settings and uncheck the box for Align heads manually, then you'll have no worries..

 

[nche11]

Now that you guys are on the alignment topic I have trouble understanding Canon's algorithm behind its automatic alignment design. If you pull the print head and put it right back in for some printers they would ask you if you want to align the print head. If you press OK button these printers would go off and keeping whining for a few minutes in doing the alignment. The problem is how would these printers know there is no need to prime the print head first? What if there is a problem with the print head for example there is an air pocket created as a result of pulling the print head? By going off to align the print head without priming first could cause the print head damaged.

I have had this question in mind for a long time with no answers. If my printer asks me if I want to do an alignment I always click no. If I feel I need an alignment I would invoke it myself. I just never let my printer initiate it by itself.

 

[stratman]

The problem is how would these printers know there is no need to prime the print head first?

According to service manuals I have read, the printer should prime the print head whenever a print head is installed. Whether it is a new print head or the same one you just took out and put back in, it would make sense for Canon to do this automatically to prevent problems most likely in a "warranty" situation.

The printer only "knows" that there was no print head installed and now there is a print head installed. The printer then initiates the programmed response asking if you want an alignment. The decision to align is left up to you.

 

[l_d_allan]

You got it backwards. You want to pick the one that is the most solid, with the least amount of lines.

Makes sense ... thanks for clearing up my confusion on this ... glad I asked.

When I look at the alignment printout again, I see that the extreme values for the working nozzles go from +7 to -3, and the vertical lines are most evident at those extremes. The rectangles get more solid as the alignment values get closer to zero, and typically something from -1 to +1 are the most solid.

I suppose a process of elimination would lead to concluding that since it can't be both +7 and -3, it must be the most solid. However, it could be that alignment values of +7 and -3 are equivalent due to "roll-over". Or not. I guess I'm easily confused.

The Canon alignment instructions are:

Execute print head alignment. Examine the printed patterns, and enter the
pattern number of the pattern with the least noticeable streaks in the fields
for columns A to H.

To me, "least noticeable streaks" doesn't mean the same as "most solid". I wouldn't call quite distinct vertical lens as equivalent to "most noticeable streaks", but ...

 

[ghwellsjr]

It's probably a Japanese-English translation.

 

[Redbrickman]

If it's the Pro 9000 MK2 that you are aligning then just let it do it for you.

Unless there is something seriously wrong after you let it do an automatic alignment I would accept it as OK.

 

[l_d_allan]

If it's the Pro 9000 MK2 that you are aligning then just let it do it for you.

Agree. I was unclear on what alignment involved.

I suppose the printers have some kind of optical sensor to decide what values to use for automatic alignment. I'm impressed it can do that with a high degree of accuracy for the reasonable cost of the printer (but granted the price is subsidized by the anticipated revenue stream from ink sales).

 

[ghwellsjr]

Yes, many Canon printers have an optical sensor mounted on bottom left-hand side of the carriage. You can probably find a couple wires that go down there. The sensor really only has to look for the point at which the reflected light amplitude is the most steady.

It would be an interesting exercise for you to have the printer do the alignment automatically and see what numbers it come up with and then do it manuallty to see if there is any change.