Mobile phones come in a variety of different physical styles or form factors that define the design and shape of the device and the arrangement of the various elements on it. Manufacturers are continuously striving to make mobile phones thinner and lighter and to come up with innovative designs. Different form factors for cell phones affect the size (and therefore the portability), functionality, ergonomics and usability of these devices. Users may prefer one form factor over the other based on their specific preferences and requirements.Though there are many form fac tors available in the market, most mobile handsets can be classified under the following broad categories:
Bar
Also referred to as “candy bar,” this is the most basic of handset form factors. Like a bar of chocolate, the phone is rectangular in shape, and does not have any hinges or moving parts. You’ll find a display screen and the standard set of number keys. Depending upon the specific phone model, you may also find soft keys, ‘answer’ and ‘end’ buttons, and navigation keys. The screen and all these keys are placed on the front of the device. Since the keys are exposed, most phones using this form factor also provide a key- guard feature that prevents the keys from being pressed accidentally when it’s in your pocket.
Clamshell
Also referred to as folder, a clamshell phone consists of two halves joined by a hinge. The upper half usually sports the screen and the speaker, while the keys are placed on the lower half. The phone is shut when not in use, hiding the screen and buttons. Most clamshell phones also boast if dual LCD screens: apart from the main screen on the inside, there is also a secondary, smaller screen on the outside that displays information
such as the time, battery status, caller information etc. Depending upon the model, the two screens can have different screen resolutions and colour capabilities. Most phone models using this form factor have also an ‘Active flip’ feature, which means that calls can be answered and ended by opening and closing the phone. In most cases, the size of a clamshell phone is quite com pact when closed as compared to candy bar phones.
Flip
A flip phone is across between the bar and clamshell. Here, most components including the screen and the keys are placed on bottom half of the phone. The top half is usually a plastic flap that folds on top. Again, depending upon the phone model the top half may contain a speaker and even a transparent that enables the user to see a portion of the screen phone is closed. The visible part of the screen display the time and caller ID information. Most flip phones also have active flip feature.
Slider
A relatively newer entrant, phones using a slider form factor are designed much like clamshell phones. The phone has two parts one with the screen and speakers along with some keys, and the other half containing the main keypad. However, instead of folding, the bottom half with the keypad slides out from under the top half. This kind of design also allows the phone to be quite small. Also, in most cases, you can perform certain operations such as answering and ending calls and accessing the phone book and call history without opening the slider.
