Inspecting Laptops Through Production from Displays to Keyboards to Surfaces

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In consumer electronics, a flawless device is a prerequisite to market success, along with a tight handle on production throughput and waste. Automated imaging solutions integrated at strategic points along the production line can provide the control needed to ensure product quality and process efficiency, without the need for human intervention.

However, there are certain kinds of imaging technology that offer capabilities beyond traditional machine vision inspection to qualify devices using the visual sensitivity and determinations of a human observer. Photometric and colorimetric imaging solutions provide absolute measurement of luminance and chromaticity values, using CIE-matched filters and calibrations for quality that emulates human visual perception of light. Beyond this, technical advantages of photometric imaging for anomalous defect detection (such as detecting broad areas of non-uniformity in displays) can be applied to device glass and other surfaces to catch flaws that appear as random and unexpected, grading the severity of defects using “just noticeable difference” (JND) calculations. This application of imaging to surfaces in addition to a device’s light-emitting areas (like the keyboard or display) provides a single solution for total device quality, regardless of the production stage or component under test.

Radiant ProMetric Imaging Colorimeters and Photometers are applied by major consumer electronics manufacturers worldwide to provide detailed measurements of the luminance, color and uniformity of displays from LCD, LED, OLED, mini- or micro-LED and beyond. Systems implemented throughout the manufacturing process control all aspects of a display-based device, including backlight units, emitting layers, glass and surfaces, keyboards and device features. Defects like poor display performance, dead pixels, mura, particles, scratches, dents and fingerprints can be detected even at low contrast utilizing broad dynamic range, CCD cooling to reduce image noise (and improve accuracy), and camera resolutions to 29 megapixels. Paired with Radiant TrueTest software, photometric imaging systems are equipped with a range of display and surface inspection tests that can be run in sequence to automatically pass/fail devices as they move through production.

In addition to enabling pass/fail automation on the line, Radiant cameras have been used to improve materials efficiency for high-value display technologies. Emissive displays like OLED and LED are made up of individual light-emitting units (either LEDs or pixels). Because they receive individual inputs, the output of each of these units can be adjusted to correct non-uniformity issues in the display (from LED to LED, or pixel to pixel, or across broad areas of the display). Radiant photometric imaging systems calculate discrepancies in luminance and color at the LED, pixel, or subpixel level and then use these values to apply correction factors, enabling manufacturers to prevent material waste.

By identifying defects as early as possible on the line, Radiant’s photometric imaging systems facilitate lean operations by improving efficiency, lowering production costs and reducing material waste, while ensuring absolute quality of devices from display to final mechanical assembly. Capable of light measurement and surface inspection, Radiant photometric imagers offer a complete solution for imaging and analysis that increases efficiency for comprehensive quality control throughout electronics production.