Transparent Windows
Display Criteria for InspectionsInspections are performed over a fixture with the LED or LCD display that is used in the end product.
If a fixture is not available, a rheostat-controlled light table will be used to approximate the light intensity of the display and with a transparent overlay that is the same color as the display. Viewing time will be:
• Two seconds for every three square inches of window up to 12 square inches.
• One second for every three square inches beyond 12 square inches.
Using this procedure, no visible flaws, foreign matter, pinholes or color variation are allowed.
Color Inspection Procedure
All colors must be within 3.0 (Delta E color tolerance measurement) of the approved color swatch when measured on a computer photospectrometer.
1. To visually compare colors, we place the printed part against the original swatch. Then we place a neutral gray viewing mask, positioning one hole over the newly printed part, and the other hole over the original swatch. (See illustration below.)
2. Ideally, this should be done in a viewing booth with a 5000 Kelvin light source. In the absence of a viewing booth, cool white fluorescence emitting 75 to 100 foot candles should be used while taking care to not have ambient color reflections on the part.
3. There should be no discernable color variation when viewed using this procedure.
4. Back-lit colors and window colors are compared over the light fixture furnished – with the actual light source in it – to verify that the color matches the original swatch.
