Velocity Measurement Instrument Project

[sunshine]

I'm a college freshmen engineering student. I'm working on a project right now with the goal of designing a velocity measurement device for a large printer, something that might be found on a printer like the iGen4. I'm looking for any info which might benefit us in this project. What kind of problems arise from paper velocity issues? Do most printers have multiple velocity measurement devices throughout the machine? What kind of technology is usually used to control paper velocity? Thanks.

 

[SuperGroup]

Hey me too whos your teacher?

 

[sunshine]

Prof Conrad Tucker

 

[iGenTech]

Sunshine,

Paper motion on most printers is based on fixed RPMs 50/60hz of the paper path motors. On most there is a master clock we call machine clock that's the speed of the photo belt.

On the igen 4.
From the time a page is feed to the time it is stacked it is under the control of paper path motors. Most of which are stepper/servo motors with build in incoders to monitor the velocity of the motor. Paper path timing is measured starting with the lead edge of the page to the trail edge and lead edge to lead edge from sensor to sensor. There are over 50 paper path timing sensors in a igen4.

Most of the sensors are not critical timing sensors. The problem is paper path rolls the move the paper ware out at different rates. This results in the papers velocity being wrong. A good example was just a few post back. The per fuser was running at the right speed but the fuser roll was runing slow causing the paper to bow up and hit the under side of the fuser ram assy. I had this happen just last week do to a new fuser roll that was to small.