Paper cup vision inspection lighting determines whether a defect is visible in the captured image. A glossy coating, curved sidewall or changing print background can hide the feature that an inspection tool needs. Improving the decision threshold cannot recover detail that the camera never captured clearly.
This guide concerns an installed or proposed inspection system. Camera inspection is configuration-dependent and is not claimed as standard on every HANNAI machine. Have the integrator approve lighting, camera and trigger changes and verify their compatibility with the actual line.
Diagnostic decision table
| Image symptom | Comparison to capture | Potential confusion |
|---|---|---|
| Bright patch hides a defect | Cup rotation and light geometry | Reflection is mistaken for a sound surface |
| Stopped images work but moving images fail | Approved-speed acquisition | A static image overstates detection |
| Dark artwork triggers rejects | Good and defective print variants | Print contrast is mistaken for damage |
| Results change during a shift | Ambient light and acquisition records | Software thresholds are blamed first |
Define the visible feature and inspection zone
Specify the defect to be detected and the part of the cup that must be visible. Assemble known acceptable and defective samples whose classifications have been agreed independently. Include realistic coating finishes and artwork variants. A demonstration using only a blank white cup does not establish performance on every printed design.
Record whether the task concerns presence, shape, print or another visible characteristic. A camera looking at one exterior view cannot automatically verify hidden layers or liquid integrity. Define the inspection coverage explicitly so the final acceptance report does not imply that unseen surfaces were examined.
Preserve the raw acquisition baseline
Save representative unannotated images and the associated acquisition settings before changing the system. Record camera, lens, working distance, light type, mounting geometry and trigger arrangement. Include the cup orientation and production condition. Keep software overlays separately so they do not obscure the feature being reviewed.
Cognex documentation illustrates that exposure, gain and illumination are separate acquisition controls, with some options dependent on the connected hardware. Use the installed system documentation rather than copying another camera model’s settings. A visually brighter image is not necessarily a better inspection image if relevant detail has been lost.
Challenge reflection and background variation
Capture each representative sample through the orientations and positions that occur in production. Compare how the defect and surrounding acceptable material appear. With the integrator, evaluate an appropriate lighting arrangement for the feature; do not select a light simply because the whole cup looks attractive in a photograph.
Include likely ambient-light conditions and approved enclosure arrangements in the trial. Check that suppressing a reflection does not also suppress the defect signal. Where a specialized glare-removal mode is available, confirm its hardware and motion requirements. Features advertised for one vision platform do not establish compatibility with another installation.
Validate acquisition at operating conditions
Collect images while cups move under the approved production conditions, using the normal trigger and handling path. Review motion blur, cup positioning and whether the complete inspection region appears at the required moment. Compare these images with the stopped baseline instead of judging the system from static samples alone.
Maintain sample identities so a missed detection can be linked to its actual image. Distinguish an acquired image classified incorrectly from a trigger that produced no usable acquisition. Review the timing and processing constraints with the integrator before adopting any mode that captures or combines additional images.
Separate image quality from decision validation
Once the feature is consistently visible, evaluate the inspection decision using an independent challenge set. Keep false accepts and false rejects separate by defect and artwork. Confirm the physical reject outcome using the approved challenge procedure; successful image analysis alone does not verify that the correct cup is removed.
Control the final acquisition and inspection versions and retain reference images. Define which changes in artwork, coating, camera position or lighting require review. Send HANNAI and the integrator the original images, sample classifications and acquisition conditions so a recurring problem can be traced to optics, presentation or decision logic.
Related equipment and next checks
Review the paper cup production line configuration and the related guide to reject-system challenge testing. The Engineering Notes archive connects these checks with wider machine planning.
Technical reference
- Cognex: acquisition settings and hardware-dependent imaging modes — general reference; confirm applicability to the installed equipment.
Frequently asked questions
Can a threshold fix a defect hidden by glare?
It cannot restore image detail that was not captured; review acquisition first.
Does a good stopped image validate moving cups?
No. Test the actual motion and trigger conditions.
Is a vision system standard on every machine?
No. Confirm the installed or quoted configuration.
Does camera acceptance prove liquid integrity?
No. Validate the relevant functional requirements separately.
Review the evidence with HANNAI
Send your machine model, component identification and the observations described in this guide. Include the drawing or material reference and any before-and-after measurements so the required next check can be identified.