Chromasens Optical Inspection System for Digital Printing Automatically Detects Costly Errors
KONSTANZ, GERMANY -- Digital printing has emerged as a cost-effective alternative to traditional offset printing, particularly for small to mid-size runs. Using toner or inkjets to print directly from digital files, digital printing reduces prepress times and eliminates the need for offset printing plates. Also, since digital printing is an "on-demand" technology, it offers greater flexibility for variable data output and faster turnarounds between jobs.
Like offset printing, digital printing must be automatically inspected for errors, especially during high-value production runs. Digital printing systems often have built-in spectrophotometers or densitometers to measure color accuracy, along with sensors for detecting misalignment of colors or elements. However, for detecting issues like streaks, banding, smudging, or missing pixels caused by clogged inkjet nozzles or toner inconsistencies, industrial line scan cameras are a must.
THE CHROMASENS SOLUTION
Drawing from its industry-leading, customer-proven imaging product line, Chromasens has assembled an engineered solution for digital printing inspection, consisting of a high-resolution color line scan camera, an LED bright field illumination system, an LED controller, and optional adapters. By catching defects early, the Chromasens in-line system prevents wasteful production of faulty prints. It also minimizes reprints and customer dissatisfaction.
At the center of the system is the Chromasens allPIXA evo 15k DXGE, a Dual 10 GigE interface camera that achieves fast RGB color scanning with line frequency rates up to 49 kHz from its 15k (15360 pixels x 4 lines) Quadlinear CMOS sensor. Equipped with line and frame trigger options, SFP+ optical connectors, variable encoder input, and color conversion possibilities, the allPIXA evo 15k DXGE is the best choice for digital print inspection. For easier integration, the camera comes with an intuitive graphical tool and an SDK for camera control and image capture for both Windows and Linux. Plus, it improves affordability by using cost effective network interface cards for 10 GigE. Chromasens recommends partnering the allPIXA evo 15k DXGE with an APO-Rodagon 105/4.0 lens.
Line scan cameras capture a single row of pixels at a time, requiring intense and consistent illumination to achieve adequate exposure during the brief scan period. To optimize the performance of the allPIXA evo 15k DXGE, Chromasens combines the camera with its Corona II Bright Field illumination system delivering ultra high intensity light up to 300,000 cd/m² in a module length of 680 mm (2.23 feet), ideal for limited installation space. Bright lighting compensates for the reduced light collection due to the narrow field of view and fast scanning rates, preventing underexposure and ensuring adequate image contrast and detail. The Corona II utilizes water cooling to minimize heat's impact at the print head and to promote a longer service life for the LEDs. A patented reflector shapes the light and directs it onto the printed material being inspected.
To control Corona II LED brightness, Chromasens pairs it with its XLC4 LED Controller that serves as an external power supply with adjustable current. It ensures the optimal spectral behavior of LEDs by delivering high continuous power of 80 watts per channel and preventing brightness variations in the images. Its flash is capable of an extremely fast 60 kHz, plus the controller can monitor temperature for the water cooling.
Additionally, Chromasens offers an optional lens adapter, modular focus, camera adapter, and an M95 extension to round out its inspection system.
Chromasens has a long history of innovation in line scan systems that boost the quality and efficiency of modern printing operations, addressing the increasing demands for precision and defect-free products in web, flexographic, offset and digital printing applications.