The form factor of a mobile phone is its size, shape, and style, as well as the layout and position of its major components.
A bar (also known as a slab, block, candybar) phone takes the shape of a cuboid,[1] usually with rounded corners and/or edges.
However, "brick" has more recently been applied to older phone models in general, including non-bar form factors (flip, slider, swivel, etc.
), and even early touchscreen phones as well, due to their size and relative lack of functionality compared to current models on the market.
[7] A slate is a smartphone form with few to no physical buttons, instead relying upon a touchscreen and an onscreen virtual keyboard for input.
[9] The success of the iPhone, which was released by Apple in 2007, is considered by some to be largely responsible for the influence and achievement of this design as it is currently conceived.
Some unusual "slate" designs include that of LG New Chocolate (BL40), or the Samsung Galaxy Round, which is curved.
The presence of the front camera for taking selfies has been an essential feature in smartphones, however, it is a difficulty to achieve a bezelless screen as is the trend in the later 2010s.
[10][11][12] Xiaomi revealed Mi MIX Alpha, a smartphone with a display that surrounds almost entirely its body, only interrupted in the back part by a column that contains the cameras.
[19] The second screen allows the Axon M's single camera to be both rear and forward facing, as well as acting as a kickstand or tripod.
The goal of a sliding form factor is to allow the operator to take advantage of full physical keyboards or keypads, without sacrificing portability, by retracting them into the phone when they are not in use.
The Motorola Photon Q, Danger Hiptop, Sony Mylo, and HTC Touch Pro are four primary examples.
By the late-2000s, "slider" designs reached the peak of their popularity and declined afterward, being completely replaced by slate form factors with well-developed touch interfaces.
[32] Today, manufacturers are trying to develop bezel-less smartphones; the greatest difficulty being the presence of front-facing cameras and face recognition sensors.
While most brands expand display real-estate, some depart from that approach, returning to the slider form factor;[33] like the Xiaomi Mi Mix 3,[34][35] Huawei Honor Magic 2[36][37] and Lenovo Z5 Pro.
Phones like the OnePlus 7 Pro,[39] Oppo Find X[40] and Vivo Nex[41] hide front cameras within the body of the devices in motorized pop-up modules to create a bezelless front face fully occupied by screens without any cutout while keeping a front-facing camera that can move up when required.
One major drawback with pop-up cameras is their inherent complexity due to the mechanism used, as the components such as the motor take up valuable space within the phone's internals which may also fail over time.
[44] Some implementations, that do not use the sagital axis, are presenting in phones like Nokia 3250 and Oppo N1, with twistable components: a keyboard, and main camera (doubling as a selfie one), respectively.
Bezelless Samsung A80[45] only has rear cameras that are housed in a motorized module, using a combination of slider and swivel they achieve the rotation to the front to be used for selfies.