The flip or clamshell is a mobile phone form factor which is in two or more sections that fold via a hinge. If the hinge is on a long edge the device is more likely to be called clamshell than flip phone (e.g., Nokia Communicators).
When the clamshell is open, the device is up and ready to be used. The interface components are kept inside the clamshell, which offers more surface area than when the device is closed. Interface components such as keys and display are protected when the clamshell is closed, and it is shorter and narrower, making the device easier to carry around. A disadvantage of the clamshell design is the connecting hinge, which is prone to fatigue or failure.
The clamshell form factor is most closely associated with the mobile phone market, as Motorola used to have a trademark on the term "flip phone", but the term "flip phone" has become genericized to be used more frequently than "Clamshell" in colloquial speech. The design is also used on some landline phones, particularly cordless phones. Other devices using the flip form include laptop computers, subnotebooks, the Game Boy Advance SP, and the Nintendo DS, though these are less frequently described as "flip" or "clamshell" compared to cellular phones.
The first Motorola model to support the clamshell design was the StarTAC, created in 1996, although General Telephone & Electronics (GTE) held the trademark from the 1970s for its Flip Phone (one of the first small hand-held electronic phones), until 1993.
The design has since been copied by virtually all mobile phone manufacturers many times.
Motorola is best known for its clamshell models such as the RAZR.
The clamshell design has also been used in the Nokia Communicator series, with the first model released in 1996. Early models were very expensive and Nokia did not adopt the traditional clamshell phone design until 2004.
Clamshells were, as of early 2009, the most popular form factor for cellular phones in the U.S. However, with the advent of smartphones, they have lost ground to phones with slide-out keyboards, and touchscreen slate phones.
Cellular phones are the most popular use of the clamshell form factor. The design is also used on some landline phones, particularly cordless phones. Other devices using the flip form include laptop computers, subnotebooks, the Game Boy Advance SP, the Nintendo DS, and the Nintendo 3DS, though these are less frequently described as "flip" or "clamshell" compared to cell phones.
Other appliances like pocket watches, waffle irons, sandwich toasters, krumkake irons, and the George Foreman Grill have long utilised a clamshell design; a very similar concept is used in racing and road legal cars, like the Ford GT40 and Ferrari Enzo, where the whole rear end can be lifted to access the engine compartment and suspension system.
It is also an informal name for General Motors full-size station wagons, manufactured from 1971 to 1976, that featured a complex, two-piece "disappearing" tailgate, officially known as the "Glide Away" tailgate.
- US trademark #2157939, cancelled February 26, 2005
- U.S. Patent D280,511
- U.S. Patent 4,571,456
- Tynan, Dan (2005-12-24). "The 50 Greatest Gadgets of the Past 50 Years". PC World. p. 2. Retrieved 2006-09-10.
- Sams Telephone Collection - Post Liberalisation
- "Motorola tries to secure flip phone trademark, designer gets caught in battle". Mobile Phone News. 1996.
- "Nokia takes on clamshell rivals". BBC News. 2004-06-14. Retrieved 2010-05-02.
- MSNBC: The flip phone takes a dip in popularity
- 1971 Oldsmobile station wagon (How Stuff Works)