Photoelectric sensor, or photo eye, is equipment used to discover the distance, absence, or presence of an object by using a light transmitter, often infrared, and a photoelectric receiver. They are largely used in industrial manufacturing. Photoelectric sensors are widely used in the industrial manufacturing sector as they provide a huge variety of problem solving alternatives in the industrial sensor market. Photoelectric technology has advanced a lot and a sensor is now able to detect a target less than 1 mm in diameter. Photoelectric sensors can be easily incorporated into an endless array of applications.
| Diffused mode or proximity-sensing mode | Retro-reflective mode | Thru-beam mode or opposed mode |
| Laser photoelectric sensors | Fiber optics photoelectric sensors | Remote photoelectric sensors |
| Senses all kinds of materials. | Longer life. | Better sensing range | Fast response time. |
| Cost effective | Can detects small objects including color mark and label detection. | Can detect transparent objects. | Can detect long range and it is tolerant of dirty environment. |
| Check fill level of coffee in cans | Count bottles moving on a high speed conveyor | Detect missing labels on bottles | Ensure safely control at the opening and closing of garage doors |
| Enable turning on sink faucets with the wave of a hand | Control elevators, and open the doors at the grocery store | Detect the winning car at racing events. | Detect porous targets, and invisible markings on products |
| Detect the presence or movement of an object within a defined sensing area or zone | Detect the level of contents in a hopper | Check products passage in a rinsing process | Locate the position of an automated storage and retrieval system |
| Detect the presence/absence of contents in a bottle/ milk carton | Check the passage of cars on a conveyer | Check positioning of cars in final assembly line | Check passage of engine block |