Newton Labs Flaw in the chemical coating of the web
Example of a "drag" flaw in the web's photo paper chemical coating detected by the system.

High-Speed Photographic Paper Web Inspection

Inspecting a light-sensitive product at 25 feet per second.

Diagram of the web inspection system
With help from the manufacturer, Newton engineers researched the best illumination frequency to allow optimal line scan functionality while keeping the product unaffected.


The challenge was inspecting the surface of photographic paper for defects without exposing the product to light.


Newton engineers worked closely with the manufacturer to determine a specific wavelength of infrared light (IR) that would not expose the paper and still provide sufficient illumination for a line scan imaging system.

The project employed line scan technology to inspect a high-speed web of photograph print paper running at a maximum of 25 feet (7.5 m) per second. The installation consisted of a free-standing metal frame secured permanently to the factory floor over the web. The frame housed the two-level supports for the imagers, as well as the mounting for the IR illumination bar. The frame included a precision backing roller under the web to stabilize the paper in its Z-axis while passing below the imagers.

The system was controlled with two Newton line scan control units and a PC connected to a bank of three monitors. One monitor displayed the center of the web; one monitor was a split-screen showing both edges of the web and the third displayed the User Interface and operation parameters of the web. Newton software engineers developed customized software optimized for the specific inspection tasks.


Newton Labs

Technology Applied:

High-Speed Line Scan

Location: Greenwood, South Carolina