Jog dial
Encyclopedia
A jog dial, jog wheel, shuttle dial, or shuttle wheel is a type of knob, ring, wheel, or dial which allows the user to shuttle or jog through audio
Music
Music is an art form whose medium is sound and silence. Its common elements are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...

 or video
Video
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...

 media. It is commonly found on models of CD players which are made for disc jockey
Disc jockey
A disc jockey, also known as DJ, is a person who selects and plays recorded music for an audience. Originally, "disc" referred to phonograph records, not the later Compact Discs. Today, the term includes all forms of music playback, no matter the medium.There are several types of disc jockeys...

s, and on professional video equipment such as video tape recorder
Video tape recorder
A video tape recorder is a tape recorder that can record video material, usually on a magnetic tape. VTRs originated as individual tape reels, serving as a replacement for motion picture film stock and making recording for television applications cheaper and quicker. An improved form included the...

s. More recently, they are found on handheld PDA
Personal digital assistant
A personal digital assistant , also known as a palmtop computer, or personal data assistant, is a mobile device that functions as a personal information manager. Current PDAs often have the ability to connect to the Internet...

s, and as the scroll wheel
Scroll wheel
A scroll wheel is a hard plastic or rubbery disc on a computer mouse that is perpendicular to the mouse surface. It is normally located between the left and right mouse buttons.- Functionality :...

 on computer mice
Mouse (computing)
In computing, a mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons...

. "Jog" refers to going at a very slow speed, whereas "shuttle" refers to a very fast speed.

There are two basic types of wheels. One type has no stops and can be spun the entire way around, because it is a relative rotary encoder
Rotary encoder
A rotary encoder, also called a shaft encoder, is an electro-mechanical device that converts the angular position or motion of a shaft or axle to an analog or digital code. The output of incremental encoders provides information about the motion of the shaft which is typically further processed...

. This type depends on tracking the actual motion of the dial: the faster it spins forward or back, the faster it fast-forwards or rewinds. Once the dial stops moving, the media continues playing or remains paused at that point. Another type has stops on either side, and often has three or so speeds which depend on how far it is turned. Once the wheel is released, it spring
Spring (device)
A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication...

s back to the middle position and the media pauses or begins playing again.

If the device is set or designed to pause after the wheel is used, the audio is often stuttered, repeating a small section over and over again. This is usually done on DJ CD players, for the purpose of beatmatching
Beatmatching
Beatmatching is a disc jockey technique of pitch shifting or timestretching a track to match its tempo to that of the currently playing track e.g. the kicks and snares in two house records hit at the same time when both records are played simultaneously...

, and is equivalent to an earlier turntablist DJ moving a phonograph
Phonograph
The phonograph record player, or gramophone is a device introduced in 1877 that has had continued common use for reproducing sound recordings, although when first developed, the phonograph was used to both record and reproduce sounds...

 record back and forth slightly to find the physical location of a starting beat
Beat (music)
The beat is the basic unit of time in music, the pulse of the mensural level . In popular use, the beat can refer to a variety of related concepts including: tempo, meter, rhythm and groove...

 within the groove. On video, the pause is a freeze frame of the current video frame.

Sony Corporation is known to hold a patent for 5-way version of jog dial, a device allowing up and down scrolling, right and left deflections and a pressure. Such jog dial was a feature of Sony CLIÉ
CLIÉ
The Sony CLIÉ was a series of personal digital assistants running the Palm Operating System developed and marketed by Sony from 2000 to 2005. The devices introduced many new features to the PDA market, such as a jog-wheel interface, high-resolution displays, and Sony technologies like Memory Stick...

 PDA
PDA
A PDA is most commonly a Personal digital assistant, also known as a Personal data assistant, a mobile electronic device.PDA may also refer to:In science, medicine and technology:...

 series and SonyEricsson P800, P900 and P910 smartphones. 5-way jog dial is not used by Sony or its subsidiaries since 2006.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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