The tablet inspection algorithm is relatively mature at present, and the difficulty lies in obtaining high-quality images at high speed. Because the surface of the tablet is curved, the equipment using the 2D camera combination needs uniform illumination across the entire field of view to detect dirt and defects on the tablet surface, but it is difficult to achieve completely uniform light sources for highly reflective surfaces. Therefore, it is difficult to stably perform appearance inspections such as blister packaging damage due to the influence of surface gloss and curvature.
Manual inspection vs. Machine vision inspection
Using the visual system, the influence of the surface state can be eliminated and the bad situation can be accurately detected. It can meet the online inspection needs of tablet production, tablet blister packaging, and the integrity of the back of blister packaging in the pharmaceutical industry.
Inspection procedure
Inspection method
For the detection of tablet defects, methods such as Blob and template matching can be used.
1. For blister packaging defects, image comparison and height difference measurement can be used.
2. The device can also connect directly to the existing 2D detection solution, and provide image data for users to use existing algorithms such as binary edge collapse detection to detect missing, defective or foreign matter mixed with impurities by converting 3D to 2D.
Detection equipment
1. Adopt an integrated multi-camera combination method.
2. Tablet blister board detection: The assembly line moves at high speed in the Y direction under the camera. The camera completes high-speed scanning of the material according to the production rhythm. When the unqualified tablet moves to the specified position, the rejection device removes the problematic tablet board. Complete high-speed scanning of at least 1 meter per second.
Performance
1. Beat: 1m/s (covering 100mm standard tablet plate, more than 400,000 tablets/hour)
2. Corner missing, cover falling, fragments, cracks, tablet body defect exceeding 1%
3. Black spots or marks not less than 0.4 mm2
4. Coating missing not less than 0.4 mm2
5. Sticking tablet marks not less than 0.4 mm2
6. Corner missing – tablet corner missing not less than 1% area or volume.
