Crack and dirt inspection and counting of eggs
Eggs rotate on a six-lane roller conveyor as they pass through a cabinet. Cracks are searched with candling light from below and shell dirt with diffuse light from above; every row is counted and a defective egg is moved to a separate lane at the exit.
The lane and row number of a defective egg are sent to the PLC, and at the exit the pin of that lane lowers the egg onto the lower belt. The total count and the breakdown by defect type are written to the production record.
- 01 Infeed
- 02 Candling
- 03 Top light
- 04 Analyse
- 05 Reject
Eggs arrive six abreast, rotating on the rollers.
- Eggs counted
- —
- Eggs in row
- —
Scenes are illustrative simulations; they are not customer references or performance guarantees.
Need
A hairline crack is too fine to see on the shell surface and may be on the face that is hidden at that moment. Shell colour and speckles vary from egg to egg, and a dirt stain is easily confused with natural speckling.
Solution approach
Strong light from below passes through the shell; more light leaks along a crack, so the crack shows as a bright line. In a second image taken under diffuse top light, dirt on the shell surface appears as a dark stain. Because the rollers turn the egg, successive images cover the whole shell, and the eggs in the row are counted from the same image.
Process steps
- 01
Infeed
Eggs arrive six abreast, rotating on the rollers.
- 02
Candling
Light is applied from below and an image is taken in transmitted light.
- 03
Top light
An image of the shell surface is taken under diffuse top light.
- 04
Analyse
Bright lines (cracks) and dark stains (dirt) are searched; the row is counted.
- 05
Reject
At the exit the defective egg is lowered onto the lower belt and taken to a separate lane.
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