Leuze Easy Learning Classroom Practical Knowledge Sharing - Principle and Application of Ultrasonic Sensors

Optical Sensor is a device that converts light signals into electrical signals. It plays a vital role in automated production. With its excellent performance and wide applicability, Leuze optical sensors have become experts in this field. Its products are widely used in logistics automation, packaging industry, automotive industry, electronics industry, lithium battery industry and other fields. Today, let us explore the principles of optical sensors.

Composition of photoelectric switch

Photoelectric switch is the most basic form of optical sensor, which is mainly composed of light source, photodetector, switch circuit, etc. When an object blocks the light, the light signal received by the photodetector is weakened, thereby triggering the switch circuit and outputting an electrical signal. Leuze optical sensors use advanced photoelectric detection technology to achieve high-precision light signal detection, thereby ensuring the accuracy of the switch.

Spectrum and light source type:

The spectrum refers to the characteristics of light distribution according to wavelength or frequency. The spectrum of Leuze optical sensors includes visible light wavelengths (390~780nm) and infrared light wavelengths (780nm~1mm), which are suitable for different application scenarios. The main light source types include LED light source, infrared light source, laser light source, etc.

LED light source: The light spot is visible and divergent, easy to install and adjust, and is an economical photoelectric light source.

Infrared light source: mainly divergent light source, with strong anti-interference ability, but the light source is invisible and inconvenient to adjust.

Laser light source: long transmission distance, small light spot, high light intensity, strong anti-interference ability, suitable for detecting small objects.

Optical sensor classification and working principle

The working principle of optical sensors is mainly to convert light signals into electrical signals through the photoelectric effect. Leuze optical sensors use three principles: mirror reflection, diffuse reflection and through reflection to achieve measurement.

Retro-reflective optical sensors

The transmitter and receiver of the retro-reflective sensor are in the same device, and a reflector needs to be installed on the opposite side to return the light signal through the reflector. When an object blocks the reflector, the sensor will output a response signal.

advantage

Reduced installation (1-time wiring, installation, alignment)

Reduced space (with flat reflectors)

Suitable for detecting reflective or transparent objects

Compared with through-beam sensors, it has higher economic benefits

Disadvantages

Compared with the detection method of beam detection, the working distance is shorter

When the reflector reflects far away, the light spot is not easy to find and it is difficult to install.

Through-beam optical sensor

The through-beam detection mode requires the transmitter and receiver to be installed opposite each other to ensure that the receiver can receive the light emitted by the transmitter. When the object to be measured blocks the light beam, the sensor will sense it and make a corresponding signal output.

advantage

Very large working distance

Smaller objects can be detected using slits, holes or laser light sources

Stable detection of objects on shiny surfaces

Disadvantages

Relatively high cost (requires more materials and installation time since the transmitter is separate from the receiver)

Double the workload, more installation, alignment, wiring required

Not suitable for detecting transparent objects

Diffuse optical sensor

Like the mirror reflection sensor, the diffuse reflection sensor has the transmitter and receiver in the same device. However, the diffuse reflection sensor detects light diffusely reflected from the surface of the object instead of from the reflector. In this way, only a small amount of light can be reflected back to the sensor. This means that its working distance is shorter.

advantage

Simple and economical detection

Easy installation (no reflector or receiver required)

Space-saving, suitable for installation in narrow spaces

Disadvantages

Shorter sensing distance than retro-reflective and through-beam sensors

Greatly affected by the color, size and surface material of the object being tested

Leuze provides reliable and efficient optical sensor solutions

Leuze offers a range of reliable and efficient optical sensor solutions. The detection of objects with different surfaces, sizes and colors requires different functional principles. All different operating principles are included in a series (sizes), and the universal series can also provide extended variables and other functions. Bring specific advantages to your application.

The Leuze 5B series sensors are flexible in operation and provide excellent cost-effectiveness. They are often the best choice in systems that require the use of a large number of sensors. They are suitable for presence monitoring in the logistics industry, packaging processes and the automotive industry.

Leuze 36 series optical sensors offer excellent performance at a more competitive price. They can easily cope with the high requirements for stable sensor detection in the logistics industry, packaging systems and automotive industry.

The Leuze 53C and 55C small stainless steel housing sensors are ideally suited for hygiene-sensitive production and packaging processes. Both products feature a high-quality, extremely smooth V4A stainless steel housing and a glass-free, scratch-resistant optics cover.