Proximity sensor

src: s3.electrodragon.com

Distance sensor is a sensor that can detect the presence of nearby objects without any physical contact.

The proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for example), and seeks changes in the field or return signal. The perceived object is often referred to as a proximity sensor target. Different proximity sensor targets require different sensors. For example, a capacitive distance sensor or photoelectric sensor may be suitable for a plastic target; Inductive distance sensors always require metal targets.

The maximum distance this sensor can detect is the "nominal range". Some sensors have a nominal range setting or means to report the detection distance passed. Some people know this process as "thermosens".

The proximity sensor can have high reliability and long functional life due to the absence of mechanical components and the lack of physical contact between sensors and perceived objects.

Proximity sensor is usually used on mobile devices. When the target is within its nominal range, a device lock screen UI will appear, resulting in what's known as sleep mode. After the device awakens from sleep mode, if the proximity sensor target is still for a long time, the sensor will ignore it, and the device will eventually return to sleep mode. For example, during a phone call, the proximity sensor plays a role in detecting (and skipping) the unintentional touch of the touch screen when the phone is held to the ear. The proximity sensor is also used in machine vibration monitoring to measure the distance variation between the shaft and its support bearings. This is common in large steam turbines, compressors, and motors that use arm-type bearings.

The International Electrotechnical Commission (IEC) 60947-5-2 defines the technical details of the proximity sensor.

Proximity sensors adapted to very short distances are often used as touch switches.

Video Proximity sensor

Touch and air signal

Proximity sensor can be used to recognize air movement and hover manipulation. The range of remote sensing elements can replace vision cameras or depth camera-based solutions for hand motion detection. In particular, the car infotainment system (7 inches - 14 inches) in the vehicle can use proximity sensor to cover the sensing area above the screen. For example, LG Electronics recently filed several patents that discuss this advanced technology.

Maps Proximity sensor

Sensor type

Capacitive
Capacitive displacement sensor
Doppler effect (sensor based on doppler effect)
Eddy-currently
Inductive
Magnetic, including the magnetic proximity axis
Optics
- Photoelectric
- Photocell (reflective)
- Laser reconnaissance
- Passive (like a charge-coupled device)
- Passive thermal infrared
Radar
Reflection of ionizing radiation
Sonar (usually active or passive)
Ultrasonic sensor
Optical fiber sensor
Hall effect sensor

src: www.kiatronics.com

Apps

Parking sensors, systems installed in car bumpers that detect the distance to the nearest car for parking
Land proximity warning system for aviation security
Vibration measurements of the rotating shaft on the machine
Dead center (TDC)/camshaft sensor in reciprocating machine.
Sheet breaker in paper machine.
Anti-air battles
Roller coaster
Conveyor system
Drinks and food can create lines
Mobile devices
- Touch screen close to face
- Mute the radio power near the body, to reduce radiation exposure
Automatic faults