The display responds to three sensors (four on the iPhone 4). A proximity sensor deactivates the display and touchscreen when the device is brought near the face during a call. This is done to save battery power and to prevent inadvertent inputs from the user's face and ears. An ambient light sensor adjusts the display brightness which in turn saves battery power. A 3-axis accelerometer senses the orientation of the phone and changes the screen accordingly, allowing the user to easily switch between portrait and landscape mode.Photo browsing, web browsing, and music playing support both upright and left or right widescreen orientations.Unlike the iPad, the iPhone does not rotate the screen when turned upside-down, with the Home button above the screen, unless the running program has been specifically designed to do so. The 3.0 update added landscape support for still other applications, such as email, and introduced shaking the unit as a form of input.The accelerometer can also be used to control third-party apps, notably games. The iPhone 4 also includes a gyroscopic sensor, enhancing its perception of how it is moved.
A software update in January 2008allowed the first-generation iPhone to use cell tower and Wi-Fi network locations trilateration,despite lacking GPS hardware. The iPhone 3G, 3GS and 4 employ A-GPS, and the iPhone 3GS and 4 also have a digital compass.
Audio and output
One of two speakers (left) and the microphone (right) surround the dock connector on the base of the original iPhone. If a headset is plugged in, sound is played through it instead.
The bottom of the iPhone sports a speaker (left) and a microphone (right) flanking the dock connector. One loudspeaker is located above the screen as an earpiece, and another is located on the left side of the bottom of the unit, opposite a microphone on the bottom-right. The iPhone 4 includes an additional microphone at the top of the unit for noise cancellation, and switches the placement of the microphone and speaker on the base on the unit—the speaker is on the left.Volume controls are located on the left side of all iPhone models and as a slider in the iPod application.
No comments:
Post a Comment