Laser printer toner transfer methods

[yoeljacobsen]

I have a question regarding the theory of color laser printer operation.

Going through the service manuals of a few machines, I noticed two patterns (if I read correctly):

1. The toner is transferred directly from the drums to the paper (for instance - Brother MFC-L series).
2. The toner is transferred to the belt and from the belt to the paper (for instance - Kyocera M6035, Lexmark cs720de)

What are the pros and cons of each method? does it affect the print quality and amount of toner waste?

[Phil B.]

Re: Laser printer toner transfer methods

I have a question regarding the theory of color laser printer operation.

Going through the service manuals of a few machines, I noticed two patterns (if I read correctly):

1. The toner is transferred directly from the drums to the paper (for instance - Brother MFC-L series).
2. The toner is transferred to the belt and from the belt to the paper (for instance - Kyocera M6035, Lexmark cs720de)

What are the pros and cons of each method? does it affect the print quality and amount of toner waste?

i suggest you register your profile...

all of your questions are explained in the manual

Reading Required

[tsbservice]

Re: Laser printer toner transfer methods

I have a question regarding the theory of color laser printer operation.

Going through the service manuals of a few machines, I noticed two patterns (if I read correctly):

1. The toner is transferred directly from the drums to the paper (for instance - Brother MFC-L series).
...

Not quite true i.e. MFC-L9570CDW uses transfer belt.
Generally speaking most(if not any) modern A3 devices use belt system. Especially color devices because it allows much more precise color quality and color registration control thus high quality.
But transfer belt requires some physical space and cost. You cannot put it in small cheap A4 device

[yoeljacobsen]

Re: Laser printer toner transfer methods

Not quite true i.e. MFC-L9570CDW uses transfer belt.

Yes, it does have a belt, but look a the paper path from the service manual:

Screenshot from 2021-05-20 20-00-18.jpg


And the description of the belt (p. 2-9): "Feed the paper to the drum unit and transfer toner on the paper. "

[Phil B.]

Re: Laser printer toner transfer methods

Yes, it does have a belt, but look a the paper path from the service manual:

[ATTACH=CONFIG]49200[/ATTACH]


And the description of the belt (p. 2-9): "Feed the paper to the drum unit and transfer toner on the paper. "

it is done on the transfer belt that MOVES the paper.

[tsbservice]

Re: Laser printer toner transfer methods

it is done on the transfer belt that MOVES the paper.

Correct brother. Again due to small footprint of A4 devices and depending on design sometimes there is no different way for paper sideways.

[yoeljacobsen]

Re: Laser printer toner transfer methods

it is done on the transfer belt that MOVES the paper.

So is it really a transfer belt?

What did Brother gain from this method? After all, it forced such a convoluted paper path vs. using the belt for primary/secondary transfer?

[Phil B.]

Re: Laser printer toner transfer methods

So is it really a transfer belt?

What did Brother gain from this method? After all, it forced such a convoluted paper path vs. using the belt for primary/secondary transfer?

with a color machine the color toners have different biases ... therefore a different charge is needed to transfer the toner from drum to page... the 4 rollers in the T belt provide the needed charge to do that.

here again that info is covered in the Service manual

[yoeljacobsen]

Re: Laser printer toner transfer methods

here again that info is covered in the Service manual

The manual describes the how, not the why (the engineering compromises).

[tsbservice]

Re: Laser printer toner transfer methods

So is it really a transfer belt?

What did Brother gain from this method? After all, it forced such a convoluted paper path vs. using the belt for primary/secondary transfer?

Yes it's transfer belt.

Besides you're asking some abstract questions neither of us can know answers. We are service engineers not design engineers nor accountants.

[yoeljacobsen]

Re: Laser printer toner transfer methods

Yes it's transfer belt.

Besides you're asking some abstract questions neither of us can know answers. We are service engineers not design engineers nor accountants.

Well, I hoped the "hands-on" experts will have some insight into this topic

Thank you for replying and sorry for the impractical question.

[slimslob]

Re: Laser printer toner transfer methods

The main difference between a direct to paper system and an ITB, Intermediate Transfer Belt, has to so with the paper.

1. Drums last longer when they are not subjected to contact with the potentially abrasive surface of the paper.
2. Different types and thicknesses of paper require different transfer currents. With an ITB system only the current of the PTR, Paper Transfer Roller, need to be adjusted.
3. ProCon, Process Control, to maintain print quality is easier with an ITB. Individual color patches are applied to the ITB and read by the Image Density sensor. This allows the toner concentration in each development unit to be adjusted for optimal quality. One of the patches is printed diagonally to allow for adjusting line position of each color.

As for the systems using a belt to carry the paper past the drums, many suffer a jitter problem as the trail edge of the paper leaves the registration roller.

[Drivee]

Re: Laser printer toner transfer methods

I understand that you wish to learn something. That is ok.
Brother move to that type of print as using transfer belt will be more precise and print quality will be better, expecialy if we know that Brother have really bad print comaparing to HP/Canon. So they just follow trends.
btw, Brother dont have waste toner, all excess toner will be returned back to toner tank. That is reason why charge on corona wire will be increaed from 0% to 100% yield. New cartridge will reset charge to default.

[Guest]

Re: Laser printer toner transfer methods

I have a question regarding the theory of color laser printer operation.

Going through the service manuals of a few machines, I noticed two patterns (if I read correctly):

1. The toner is transferred directly from the drums to the paper (for instance - Brother MFC-L series).
2. The toner is transferred to the belt and from the belt to the paper (for instance - Kyocera M6035, Lexmark cs720de)

What are the pros and cons of each method? does it affect the print quality and amount of toner waste?

This is the practical advice. Brother toner is a pain, Dell has worked much better for me in the past, too. Cleaning the board with a sponge isn't going to help much Abrasives like the ones suggested are the best. I've had great success using the use of a short and mild vinegar bath and. This can polish the copper.
The quality of the toner is much more important than the quality of paper in my experience. drinking water has assisted greatly. It is important to scrub across the board since there can be clear deposits that slow the process of etching in a significant way (especially in the areas of drilling holes.
The brand of the laminator is GBC and the motor is altered (gearing shift) so as to bring the speed down considerably. this site is a good source to find out more about this.

[slimslob]

Re: Laser printer toner transfer methods

So is it really a transfer belt?

What did Brother gain from this method? After all, it forced such a convoluted paper path vs. using the belt for primary/secondary transfer?

A little late in getting into the discussion. There actually at least two kinds of transfer belts. There is the transfer transport belt like the one you posted an image of on post #4 and then there are Intermediate Transfer Belts as used in most modern color machines. ITB systems mix the toner on the belt and then transfer it to the paper. They are much more capable of maintaining proper image registration between colors , both in the direction of motion and the direction of laser scan. Get a hold of some of the service manuals for older Ricoh models. They used to have a very good section on the description of how thing worked.