Optical sensors are devices designed to control distance and position, determine color and contrast marks, and solve other technological problems. The instruments are mainly used in industrial equipment.
Optical sensors are divided into three types according to the way they function.
Devices that reflect from an object are capable of emitting and receiving light that departs from an object located in their area of action. A certain amount of light is reflected from the target and, when it hits the sensor, sets the appropriate logic level. The size of the response zone largely depends on the type of device, size, color, surface curvature, roughness and other parameters of the object. In its design, the receiver and emitter are present in the same housing.
Optical sensors reflecting off the retroreflector receive and emit light that comes froma special reflector, and when the beam is interrupted by an object, the corresponding signal appears at the output. The scope of such a device depends on the state of the environment that surrounds the sensor and the object (fog, smoke, dust, etc.). In this device, the emitter and receiver are also placed in the same housing.
The third type includes optical sensors that have a separate receiver and light source. These elements are installed opposite each other along the same axis. An object that enters the region of the light flux causes its interruption, and the logic level at the output changes accordingly.
Light elements of devices can operate at different wavelengths, which include infrared or visible (laser) light, as well as other indicators of color marks.
In its design, an optical sensor consists of an emitter that generates light in different ranges, as well as a receiver that distinguishes the signal emitted by the first element. Both components of the device are located both in one and in different cases.
The operation of the devices is based on the change in optical radiation when an opaque object appears in the coverage area. When the device is turned on, an optical beam is emitted, received through a reflector or reflected from an object.
Then, a digital or analog signal with different logic appears at the output of the sensor, which is then used by the actuator or registration circuit.
Fiber optic sensors have different sensitivity zones ranging from a few centimeters to hundreds of meters.
The most convenient way is to use diffuse devices that automatically trigger on the object. For the most part, optical sensors allow you to change the settings for sensitivity and indexing of the output state, self-tuning models are also produced.
Devices on the market are represented by many manufacturers. For example, devices manufactured by AUTONICS are especially popular. They are of great variety, low price and high reliability.
