Introduction to optical forks

Optical forks are sensing devices used to detect the presence, position or passage of objects using a beam of infrared or visible light. They work through an emitter and a receiver located at opposite ends of a fork-shaped structure, allowing the light beam to be interrupted when an object passes by.

These sensors are widely used in industry, automation and process control due to their high precision, rapid response and ease of integration into production systems. Their compact design and ability to detect objects without physical contact make them ideal for applications where mechanical wear must be minimized.

Basic structure and components

The optical fork mainly consists of two parts: a light emitter and a photodetector receiver, which are located at opposite ends of a U-shaped frame or fork. The emitted light passes through the open space between both ends, creating a stable and focused beam.

The emitter typically uses a light-emitting diode (LED) that produces an infrared or visible beam. The receiver may be a photodiode, phototransistor, or a specialized photodetector that detects the received light. When an object interrupts the beam, the receiver stops receiving the light, generating an electrical signal that indicates the presence or passage of the object.

The separation between the emitter and receiver varies depending on the model and application, and can range from a few millimeters to several centimeters, a factor that directly influences the type of objects that can be detected.

Optical fork detection modes

There are mainly two detection modes in optical forks: interruption detection and reflection detection. In interruption, the beam is physically blocked as it passes an object, while in reflection, the receiver captures the light reflected by the object, although this mode is less common in traditional optical forks.

Interruption detection is the most used to count objects, measure speed or detect the position of parts in production lines due to its precision and simplicity. The sensor response is fast, allowing work at high process speeds.