All about the Sensors in an iPhone

The technology packed in an iPhone or any smartphone is so much that we often ignored that iPhones we used today are simply a sophisticated little machines. From awesome interface to face unlock , from personal assistant to track our movements, a lot of these feats accomplished through sensors in your iPhone or smartphone only. Without these sensors none of the phones will work way we love or desire. Let’s check out what are these sensors are.

True Depth Camera System
True Depth Camera system on upcoming iPhone 12: Pic credit Jon Prosser

Proximity Sensor:

Proximity sensor has been use to detect any object near the screen. It is possible due to use of an infrared LED and IR light detector. While you making a call and hold the iPhone to your ear it helps the iPhone to turn off its screen automatically to prevents you from accidentally touching the display or button taps.

Motion or Accelorometer Sensor:

The main work of this sensor to note the movement and tilt of the device so that iPhone can tell which way you hold the phone. It helps the iPhone to auto switch from landscape to portrait modes and vice versa.

Ambient Light Sensor:

This sensor is use to determine how much light is available in the surrounding to adjust the display brightness accordingly.

Liquid Contact Indicators:

A Liquid Contact Indicators gets activated when it comes contact with water or a liquid that contains water. The indicators normal Color is white or silver but it turns fully red if it contacts water. An LCI won’t activate because of humidity or temperatures changes. It is mainly use for verify the issue of iPhone due to liquid exposure or not. An LCI is mainly located in the SIM tray slot.

Face ID:

The Face ID hardware consists of Three Sensors namely namely Dot projector, Flood illuminator, Infrared Camera.

1.Dot projector:

Dot projector is mainly a structured light source or high intensity LEDs that throws a dotted light pattern onto a users face

2.Flood illuminator:

Flood illuminator is a type of module that reads the resulting pattern and generates a 3D facial map. It allows the system to detect whoever inform of the iPhone even in the low light.

3.Infrared Camera:

Infrared Camera module then read the depth map or take the infrared picture of the user.Generally in iPhone this map is compared with the registered face using a secure subsystem and the user is authenticated if the two faces match sufficiently.


Many iOS devices have three axis gyroscope to maintain a stability in navigation, image stabilisation, motion sensing control game etc. This is designed to make iPhone more sensitive, responsive and more powerful. There are many types of gyroscope sensors are used now a days.


This sensor is use to determine any phones location with the help of device’s GPS or other location sharing tools. It is mainly use for checking directions, your elevation, and to measure the inclination of surfaces.

Thumbprint or Fingerprint Sensor:

The concept is simple. Since each fingerprint is unique, once registered yours Touch ID will only be recognised. When a finger is applied to the touch pad , a steel rings sends a message to the sensor , then the biometric details are read and registered in your iPhone. Touch ID provides an added level of security to your devices and your data. Latest IPhone SE 2 still holds the Touch ID.


This smartphone technology is capable of intuitive applications due to the range of sensors integrated into this device. Though the topic is mainly a technical in nature, I just try to simplify in the common terms. There are still lots of sensors to discuss like Touchscreen sensors, Thermal Sensors etc. Touchscreens itself is a such a vast topic it will be unable to cover in one article.

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