Developing a Vision System for Recycling Printer and Fax Machine Cartridges

Author(s):
C. Bedez - Alliance Vision

Industry:
Imaging Equipment

Products:
Vision, LabVIEW

The Challenge:
Studying and evaluating the strip defects fo CTM toner cartridges to determine their suitability for recycling

The Solution:
Developing a control bench implementing a PC, data and image acquisition hardware, appropriate video cameras and a lighting system

Superior Test forRecycle Suitability
Ricoh Industrie France, a subsidiary of the Ricoh organization, manufactures digital photocopiers and CTM toner cartridges for printers and fax machines. We also recycle these cartridges in compliance with Ricoh environmental policies.

We guarantee a high-quality recycled CTM product by first verifying that all CTM components are compliant and ready for a second life cycle. The clean-up strip is a 242x12x2 mm polyurethane parallel-piped rectangle, fixed on a metal support. We realized that CTM units had two common defects affecting the strip - the strip’s position changes during normal use, and wear manifests as notches on the strip. This affects print quality by leaving marks on the paper.

To verify the position of the strip and evaluate the condition of the edge touching the printer cylinder with an application designed in LabVIEW. Various tests led us to define a maximum depth of a strip’s edge notches. If the strip is compliant, we can recycle the cartridge. If not, we dismount some of the reusable CTM unit components for retrieval.

An Integrated No-Contact Test
We used a vision system to avoid contact between the control bench and the strip resulting in further damage. The Alliance Vision Company suggested a measurement process for our application, as well as a measurement chain, including video cameras, lighting, image acquisition boards, and NI LabVIEW and IMAQ Vision software packages.

Alliance Vision provided us with training courses to learn about the software tools and start-up assistance for the project so that we could develop and control the process ourselves. Lighting up the strip and highlighting its edge was one of the key problems we encountered.

A data acquisition (DAQ) board actuates the on/off buttons of the bench, and we control the light, which varies to match the color of the strip with an analog output. We use a monochrome analog video camera connected to an image acquisition board (PCI-1408).

After the image acquisition, the user reduces a useful area of 20 pixels. We threshold the image, eliminate glitches, and extract the notches using IMAQ Vision function. With the particle analysis, we can measure notch depth and compare it to the rejection threshold. We perform the analysis on a 4 mm wide field. We perform 50 successive analyses and cover the whole strip in less than 1 min.

During the position measurement, we use two video cameras, in X and in Y positions, connected to the PCI-1408 board. We measure the points at the ends of the strip and at its center - three measurements in X and three measurements in Y. After we complete both tests, we determine if the strip is compliant.

Saving Time and Cost with NI Software
Our engineers quickly learned the LabVIEW graphical programming environment and manipulated electronic diagrams with it. The IMAQ Vision library offers high-level tools for image processing. With technical assistance from Alliance Vision we progressed rapidly and completed the application in compliance within our five-month schedule.

We appreciate the ease of use in developing this application with LabVIEW and IMAQ Vision. We are very pleased with the final bench. We can control all the CTMs to recycle, and the process is profitable. Using recycled cartridges generates significant gains, especially compared to the price of new cartridges.

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