Washing-machine porthole glass defect inspection
The deep glass bowl stops on its carrier at the photo-sensor, is lifted under a dome light and rotates about its axis; a camera above reads a narrow band from the axis to the rim, so one turn covers the whole surface. Stones, cords and edge chips are marked in place; a defective glass is taken off the line by a robot.
Defect type, position and size are logged per glass; a defective glass is taken to the reject lane by the robot, a good glass continues to assembly on its carrier, and the results are shown on the bowl map on the operator display.
- 01 Infeed
- 02 Rotate
- 03 Mark
- 04 Decide
The glass bowl arrives on its carrier; when the photo-sensor sees it, the carrier stops under the dome light.
- Stones
- —
- Cord length
- —
- Edge chip
- —
Scenes are illustrative simulations; they are not customer references or performance guarantees.
Need
The porthole glass is deep and spherical: every point of the surface has a different slope, so directional light glares on one area while darkening another. A cord is thin and long, a stone small and dark, and the thick rim hides a chip in shadow.
Solution approach
The dome light lights the surface diffusely from every direction; the sloped glass does not glare and dark refraction traces remain. The camera looks along the axis from the pole of the dome and reads only a narrow band from axis to rim; in one turn of the bowl the whole surface passes this band with the same geometry. A dark spot is a stone, a long thin trace a cord, a break in the rim a chip.
Process steps
- 01
Infeed
The glass bowl arrives on its carrier; when the photo-sensor sees it, the carrier stops under the dome light.
- 02
Rotate
The bowl is lifted and makes one full turn; the surface is imaged band by band in the diffuse dome light.
- 03
Mark
Stones, cords and edge chips are marked where they are found.
- 04
Decide
Defect type and size are compared with the acceptance limits.
Related applications
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