Throwing light on permeable work piece such as glass and film, and the image projected on a screen is visually inspected.
This method reduces the effort required of operators since it minimizes.
This allows inspection results to be confirmed by multiple people at once, which contributes to benchmarks unification.
Air trapped in production workpieces appears on the screen as bright spots as in shown.
Irregularities in layers appears as wrinkles when materials such as plastic and glass are made into boards. Projection type is suitable for surface protection detects.
Inside contamination and external scratches appear on the screen as shown.
Filter streaks are projected as shown.