Gyroscope:
An interesting feature known as 3-axis gyroscope has been added in iPhone4 and iPad2. An accelerometer generally judges the motion of the device, but 3-axis gyroscope can sense motion, speed and angle. The gyroscope and the device’s accelerometer together improve the motion sensing accuracy. It allows the device to measure that how much and how fast you are moving or rotating and in which direction. It gives better motion sensing games and applications, e.g. accurate driving games or augmented reality applications.
Ambient Light Sensor:
The Ambient Light Sensor (ALS) is used to detect environmental light. It helps to automatically increase or decrease the display backlighting to compensate for less light or more lighter. This enhances the user’s experience and saves power. These ambient light sensors can conserve battery power or provide extra safety. At the top of the phone display sensor is generally located at the top next to the earpiece. The devices like Nokia C5, C6, X6, E5, HTC HD7, Desire, Samsung Wave series, Galaxy series, etc. have the Ambient Light Sensor.
Proximity Sensor:
When the person is on the call and bring the device near the ear, proximity sensor will automatically deactivate the display and touch screen. It detects when the phone is lifted to the ear and immediately turns off the display to save power and prevent inadvertent touches. When the phone is moved away from the ear the screen turns back on. Apple iPhone, Nokia N8, C7, Motorola DEFY, Quench, LG Optimus One, BlackBerry Torch, etc are the some phones with proximity sensors.
Accelerometer sensor:
Apple's iPhone was the first Smartphone which includes accelerometer. This sensor measures the tilting motion and orientation of a mobile phone. The most common use of accelerometer is to activate auto screen rotation on mobile devices when users change their display orientation from portrait to landscape or vice- versa.
Backside Illumination sensor:
Backside Illumination Sensor, also known as Back-Illuminated Sensor is a type of an image sensor used in digital photography. This sensor is used to improve low-light performance. In this technology, the imaging components are arranged in an innovative way to increase the amount of light captured by each pixel. The first company that introduced this technology to the market at general consumer prices is Sony. This feature is included in the HTC EVO 4G and Apple iPhone 4.