MANUFACTURING
Date & Lot Code Inspection
Date & Lot Code Inspection. What it takes to run it.
Reading and verifying date, lot and part codes on the packing line against the schedule.
// 01 · The question
“Is the date, the lot and the part number on this carton the one the schedule says it should be?”
// 02 · Why it is hard
Three prints on one carton are three different reading problems. A dot-matrix date is separate dots that spread on corrugated board. A thermal label with a dead element in the print head has a white line through every character. An etched serial is bright metal on bright metal, and glare produces a plausible wrong character rather than an obvious failure. And the inkjet coder that was cleaned at the start of the day shift is a smear by four in the morning.
// 03 · What the labels have to be
Bounding box
Decided before the first frame
The date on the flap wanders as the coder fires early or late, the label sits at a different angle on every carton, and the etched serial is wherever the housing landed in the fixture. A box finds each field wherever it is, and the reader works on the crop inside it. The answer is a string of characters, not an area, so the outline of the print is worth nothing.
This is the decision that is expensive to reverse. The geometry has to match what the answer contains, and finding out it does not means labelling the set a second time.
// 03a · What it finds
The date and lot print
sprayed onto the carton flap by a dot-matrix inkjet coder as the carton passes
The label text block
part number and barcode on a printed or thermal label, at whatever angle it was applied
The etched serial
laser-etched into the housing at the previous station, wherever the fixture placed it
A missing field
a carton with no date, no label or no serial is held before it is read at all
// 03b · What it checks
- 01
The date is today's, or the shift's.
- 02
The lot is the lot the production schedule has running on this line, this shift.
- 03
The part number on the label matches the housing the line is packing.
- 04
The etched serial falls inside the range the laser was issued for this order.
- 05
A reading the reader is unsure of, or that fails any check, is a hold. The frame goes to the line lead with the crop and what the schedule expected beside it, and her call is recorded against the frame.
// 03c · What the line provides
- A camera on the packing station that sees the code at line speed. Any RTSP feed or recorder; no new camera and no new hardware on the line.
- Frames from this line, not a font file. The reader learns your coder's dots on your board, your label printer, your laser.
- The schedule, or the lot list for the shift. The checks are rules the plant already holds; the reader cannot catch a plausible wrong character on its own.
- A person to clear the held cartons. On a coded line that is the line lead, from a list, with the crop in front of her.
// 04 · How we run it
Three parts of one loop, on this job.
LexAnnotate
Defect Annotation
Pixel-level defect annotation for surface scratches, cracks, dents, weld faults, and assembly misalignments. Multi-sensor alignment for multi-camera inspection systems.
LexInsight
Line Performance
Connect defect detections to production data - batch numbers, machine IDs, shift schedules. Identify defect patterns across lines and predict maintenance needs before unplanned downtime.
LexAlert
Quality Alerts
Monitor defect detection accuracy across changing production conditions. Detect when lighting shifts, new materials, or equipment aging degrades model performance. Auto-retrain to maintain 99%+ accuracy.
// 05 · What breaks it after launch
The label is redesigned on a marketing schedule nobody told the model about. Every label is correct on changeover day and the box for the label block lands in the wrong place, because the block it learned is not where the block now is.
It is not the only one that can get this use case, it is the one that usually gets it first. All ten conditions.
// 06 · In manufacturing
Defect Detection at Scale
The Challenge
Vision models performed well in pilots but lost accuracy as factory conditions shifted.
Our Execution
Built pixel-level annotated datasets and multi-sensor alignment for reliable defect detection.
The Result
Maintained 99%+ defect detection accuracy across changing production environments. Reduced unplanned downtime.
99%+
Accuracy maintained in production
// 06a · Questions we get asked
Is this OCR or OCV?
Both, in that order. The reader turns the crop into characters, which is reading. The checks then confirm the right characters are there, legible and complete, and that they match the lot the line is running, which is verification. A code that reads perfectly but says yesterday's lot is a hold.
Why does a detector find the field before anything reads it?
Because the field moves. A crop at fixed coordinates catches the cartons that behaved and misses the date the coder fired late and the label applied at an angle. A detector with one class per field puts a box on each one wherever it landed, and the reader only ever sees the crop.
What happens to a date the reader cannot make out?
It does not go into the record. The carton is held, the frame goes to a person with the crop and the expected lot beside it, and the person reads the smear and confirms or corrects it. If it was a misread, that correction is also the hardest frame of the shift, labeled, and the model is retrained on it.
What happens when the label is redesigned?
The box for the label block lands in the wrong place on changeover day, because the block the model learned is not where the block now is. A window of frames from the first day's cartons is labeled and folded in before the run, and versions keep what they were trained on, so the old label still reads on the line that has a pallet of them left.