ColorQuick on-press color measurement system

At the beginning of 1994, the GMI Color Measurement Group started working on an on-press color measurement system for web style printing presses, accounting for the largest volume of printed material in the world. The AutoSmart® system required a sample placed on the X-Y table to be measured. An on-press measurement system could measure the printed production without the operator being involved, true closed loop control. The GMI Color Measurement Group was 2 software developers, 2 electrical engineers, one mechanical engineer. This product, ColorQuick, has been installed on hundreds of web printing presses worldwide. This product was ready to ship in mid-1995 at a major industry trade show. The unique features of this product are the dual beam spectrophotometer measurement optics and the high-speed measurement location verification. The ColorQuick system was given direct control of printing press consoles in every installation with the GMI CLC option. Measurement accuracy was critical. A critical requirement of the ColorQuick system was the customer must print a special series of colored areas for the press control to be successful without operator intervention. ColorQuick was the first successful on-press measurement system in the web press printing industry, winning the GATF 1996 InterTech Technology Award. Over 1000 ColorQuick systems were sold in 25 years globally, these color measurement systems were mechanically installed into press line machinery, costing $80,000 to $200,000 each.

Mark was specifically responsible for these features of the Colorquick product:

Firmware for the timing control of the data flow, optical flash triggers of the two optical system in probe head, using encoder signals from the press to monitor paper flow speed. One Intel 80C251 controller per probe head.

Firmware for the image processing to perform precision target adjustments of the two optical measurements in the ColorQuick probe head. The DSP processors searched the captured images of the 2mm x 4mm colorbar swatch to adjust measurement timing of the measurement optical system, placed about one inch from each other, with search and timing corrections to the measurement flash trigger occurring within 2 milliseconds at high speed paper web travelling at 3000 FPM.

Operational control of the PMD DC servo transport of the probe head across the web, to optimize the faster possible positioning of the probe heads to measure the next switch. The goal is measure one swatch per printed copy of the printed web production travelling at speeds up to 3000 FPM. The swatch commonly placed next to each other with no white space between.

PC based computer software to coordinate the timing, image processing, measurement data collection, and probe head transport movement. This computer is keep track of the colorbar location on the moving paper web, collect and verify valid measurement data and send this data back to the console computer to operator display and CLC operations.

ColorQuick UIX, Data Collection, and CLC functionality started as a MS-DOS application, then migrated to Client-Server Windows applications in 2010.(Clarios product)

The image processing kernel currently is executed by a TI TMS320C5416 digital signal processor residing on a custom “frame grabber” card.  This kernel contains all the code to handle communication messages passed from the main system operating application, and to process the captured image based on the operating mode desired.  Much of the image processing kernel is currently related to the hardware, and to the image transfer process.  The image transfer process is currently handled exclusively by hardware, and the image data is transferred from the camera to high-speed FIFO memory mapped into the DSP memory space.  The image is currently scaled such that the spatial resolution of the image is equivalent to 0.1mm per pixel. The selected device is a TMS320VC5416 that operates at 160 MIPS, four times faster than the current device,.  It is entirely possible and very likely that there will exist variations of swatch locations in capture image frames that require more than 1412 microseconds of analysis time to generate location results from the image analysis.