Vision Sensors

Why Vision Sensors?
Repetitive inspection of production lines is a labour-intensive activity that is being replaced by vision sensors which are not only cost-effective, but give consistency of judgement and documented traceability to the inspection process.

How do they work?
Vision sensors have huge numbers of photoelectric cells that capture a complete image. The amount of detail (the resolution), expressed as the pixel count depends on how many photoelectric cells the sensor contains (e.g. 1.3 million pixels). After capturing the image, the vision sensor compares some, or a number of characteristics of the image to the reference image stored in its memory. So, if the sensor is set to recognize a blister pack with eight undamaged tablets, it knows to reject a pack that has only seven tables or a broken tablet. Also the packet can be anywhere within the camera’s field of view. And it can inspect asymmetrical objects no matter how they are rotated within a full 360^o range. They have a wide variety of production applications.
Which characteristics the sensor compares to the reference image is set using software inspection tools built into the sensor. Some sensors have all the available software tools built-in and some simpler sensors have only the tool they need to do a particular task, saving cost and simplifying both set-up and operation.

The sequence begins when sensor is triggered to take an image. The sensor has been programmed to enable it locate, analyse and measure the image and then compare the results with preset pass or fail criteria. The result is communicated over Ethernet or RS232 coms ports. The Tools which enable the sensor locate, analyse, measure and decide are important features for the effectiveness and simplicity of the system. For many applications, a simple "Teach" facility is a huge benefit.

Trigger Sensor

Quick Links:
Sensor Range	Inspection Tools	P3 Kits	P4 Kits	P4 1.3 Kits	Accessories
P4 Omni	P4 Edge	P4 Geo	P4 Area	P4 BCR	P3 PRO
	Lenses	Lighting	Brackets	Enclosures

Vision Sensors can often be selected more easily from known applications where the various parts have been specified.
See Below.
Please contact us if you wish to ask for further advice or a product demonstration.

You may prefer to see the full Sensor Range

The following application examples are provided to assist in seeing the potential for vision sensors in any manufacturing environment.

APPLICATIONS:

Label Alignment

Objective: To verify that the labels on a bottle are aligned with each other and both are straight.

Sensors: Presence PLUS P4 EDGE, with LCF08 lens, HFFW12DC tubular fluorescent light, PLC used as a trigger.

Operation: Two labels are glued to the front of a bottle – one on the neck and another on the body. The Presence PLUS P4 EDGE’s Locate tool finds the edge of the bottle, and then the two Edge tools verify that the top and bottom labels are lined up and not skewed.

Complete Assembly Inspection

Objective: To verify that each end flap on a cardboard carton is glued down.

Sensors: Presence PLUS P4 EDGE, with LCF08 lens, LEDRB85X220M red backlight, fixed-field photoelectric used as a trigger.

Operation: After a cardboard carton is packed, the flaps on both ends are glued down. The Presence PLUS P4 EDGE’s Locate tool finds the edge of the box, then the Edge tools checks whether the upper and lower horizontal edges are the same distance from the centre of the box. If not, the flap is not glued, and the box fails the inspection.

Part Presence/Absence & Orientation

Objective: To verify that the cap of a washer reservoir is present and oriented within an accepted range of rotation.

Sensors: Presence PLUS P4 GEO with LCF16 lens, LEDRR62X62 red ring light, Verification Touch Button (VTB) used as a trigger.

Operation: An operator places a capped reservoir on the inspection stand. The Presence PLUS P4 GEO’s Geometric Count tool verifies that the cap is on the reservoir, that the logo is printed on the label, and that the cap is not rotated beyond the accepted range.

Component Inspection

Objective: To verify that all weld nuts in an automobile door component are present, oriented with the right side up and in the correct location.

Sensors: Presence PLUS P4 GEO 1.3 with LCF16LMP lens, HFFW24AC tubular fluorescent light, PLC used as a trigger.

Operation: Nuts are welded to a component of an automobile car door. The Presence PLUS P4 GEO uses four Geometric Count tools check whether the weld nuts are correctly oriented and aligned over the bolt holes.

Blister Package Verification

Objective: To verify that the blister packet is filled with a complete tablet of medication in each cell and that the blister is free of debris.

Sensors: Presence PLUS Pro vision sensor, LEDRB85X220W red diffused backlight, PLC used as a trigger.

Operation: A blister machine fills each cell on a web of blister packets with a tablet. Before the packets are sealed and cut, the Presence PLUS Pro uses the Blob tool function to inspect each row to verify each cell has a complete tablet inside and also ensures no broken tablets or other debris are incorrectly packaged. If a missing or partial tablet is found, the blister is rejected.

Label Positioning

Objective: To verify correct label placement on bottles of tablets.

Sensors: Presence PLUS Pro vision sensor, with LCF16 lens, LEDRR80X80W red ring light, photoelectric sensor used as a trigger.

Operation: As bottles of tablets pass on a conveyor, the Presence PLUS Pro verifies that the label is present and positioned correctly. The Edge and Measure tools measure the distance between the top of the label and the top of the bottle to check height. The distance between the side of the label and the side of the bottle is also measured to make sure the label is centred on the face of the bottle.

Assembly Verification

Objective: To verify that cloth belting has been added to a band of tyre rubber

Sensors: Presence PLUS Pro vision sensor, with LCF25R lens, LEDRA80X80W red area light, PLC used as a trigger.

Operation: On a web, cloth belting is bonded to one side of a band of hot rubber. Using the Average Grey Scale tool, the Presence PLUS Pro detects the difference between the brightness of the cloth and the darkness of the rubber to make sure the cloth has been applied to the rubber.

Part Orientation Verification

Objective: To verify that a ring is placed correctly on a component of an assembled part.

Sensors: Presence PLUS Pro vision sensor, with LCF08 lens, LEDRR80X80W red ring light, PLC used as a trigger.

Operation: An assembler places the ring over the part. The ring fits in two possible positions, but only one position is correct. The Presence PLUS Pro uses the Edge tool to check that the gasket is in the correct position, within an accepted variation of rotation.

Component Moulding Inspection

Objective: To inspect moulded plastic steering wheel components for excess or deficient material.

Sensors: Presence PLUS P4 OMNI 1.3, with LCF08LT lens and LEDRA80X80M red area light.

Operation: After a steering wheel component is removed from the mould, the P4 OMNI 1.3 inspects it for areas that received too much or too little material during the moulding process. Defective components are diverted from the line.

Toothbrush Sorting

Objective: To sort different styles of toothbrushes before they are packaged.

Sensors: Presence PLUS P4 OMNI, with LCF08LT lens and LEDRA80X80M red area light.

Operation: As toothbrushes pass on a conveyor, the P4 OMNI detects shape differences, regardless of their orientation on the conveyor. The different styles are automatically separated at the end of the line, before they are packaged.

Food Packing Inspection

Objective: To inspect boxes of chocolates for missing or damaged pieces to make sure each nest contains a candy and that the candies are not damaged.

Sensors: Presence PLUS P4 OMNI with LEDR80x80M light and LCF16LMP lens.

Operation: After boxes of chocolates are filled, the P4 OMNI checks whether the box contains the correct number of pieces. It also checks that the shapes of the candies are within tolerance, to verify that none are damaged.

Glass Vial Integrity Check

Objective: To check for damaged lips on glass vials on a high-speed filling line.

Sensors: Presence PLUS P4 OMNI with LEDRO50N light and LCF50LMP lens.

Operation: Glass vials can be damaged during filling and transfer. The P4 OMNI inspects the opening, or lip, of each vial as it passes on a high-speed conveyor to detect vials with chipped or cracked lips. If it detects any damage, it diverts the vial from the line before it is sealed and capped.