W-VHS (Wide-VHS) is a

HDTV High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the g ...

-capable

analog recording Analog recording is a technique used for the recording of analog signals which, among many possibilities, allows analog audio for later playback. Analog audio recording began with mechanical systems such as the phonautograph and phonograph. ...

videocassette Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocassette ...

format created by

JVC JVC (short for Japan Victor Company) is a Japanese brand owned by JVCKenwood corporation. Founded in 1927 as the Victor Talking Machine Company of Japan and later as , the company is best known for introducing Japan's first televisions and for ...

. The format was originally introduced in 1994 for use with Japan's

Hi-Vision MUSE (Multiple sub-Nyquist Sampling Encoding), commercially known as Hi-Vision (a contraction of HIgh-definition teleVISION) was a Japanese analog HDTV system, with design efforts going back to 1979. It used dot-interlacing and digital video co ...

, an early

analog high-definition television system Analog high-definition television has referred to a variety of analog video broadcast television systems with various display resolutions throughout history. Pre-1940 On 2 November 1936 the BBC began transmitting the world's first public re ...

Naming

JVC gives four reasons for naming the format "Wide-VHS": * Wide aspect ratio * Worldwide-usable format, conforming to foreign HDTV systems * Wide development of videotape applications * Wide (two-track) recording system

Mechanism

W-VHS VCRs can record a high-definition video signal (1035i to 1080i, stored internally as an 1125-line signal similar to Hi-Vision) via the analog Y/Pb/Pr component interface, a standard-definition signal (480i), or two simultaneous standard-definition signals, for 3D video. The recording medium of W-VHS is a -inch double-coated

metal particle tape Audio compact cassettes use magnetic tape of three major types which differ in fundamental magnetic properties, the level of bias applied during recording, and the optimal time constant of replay equalization. Specifications of each type were se ...

stored in a cartridge similar to, but incompatible with VHS. Some W-VHS VCRs are capable of playing and recording VHS and S-VHS media. Unlike normal VHS, which uses a single head to record video fields as a series of parallel standalone tracks, W-VHS uses a dual-head design to record each video field as two parallel tracks storing a

component video Component video is an analog video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video (CAV) information that is transmitted or stored as three separate signals. Compon ...

signal. The signal is recorded using a method called "time compression integration" in which the

luminance Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls withi ...

signal is divided into two sets of lines, which are then split and recorded across both tracks. After the luminance signals are recorded, the two

color Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associ ...

signals are recorded, one on each track, in a time-compressed form. Recording these signals sequentially rather than side by side prevents crosstalk between the luma and chroma components. Because the video signals are recorded in component form instead of e.g. the "color-under" method used by

S-VHS , the common initialism for Super VHS, is an improved version of the VHS standard for consumer-level video recording. Victor Company of Japan introduced S-VHS in Japan in April 1987, with their JVC-branded HR-S7000 VCR, and in certain overseas ...

standard-definition Standard-definition television (SDTV, SD, often shortened to standard definition) is a television system which uses a resolution that is not considered to be either high or enhanced definition. "Standard" refers to it being the prevailing sp ...

image quality for W-VHS is typically much higher, due to the lack of noise caused by a chroma sub-carrier. Audio is stored as a digital PCM stream.

Use

Due to its high cost, W-VHS equipment and media was distributed in the United States through JVC's professional video and broadcast equipment division and was primarily marketed for industrial and commercial applications such as

medical imaging Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to rev ...

. Currently, it is very difficult to find either W-VHS VCRs or tapes. If W-VHS media is not available, JVC recommends the use of tapes intended for the D-9 or "Digital-S" digital video format. The running time between W-VHS and Digital-S is not the same; a Digital-S tape with a length of 64 min is approximately 105 min when used with W-VHS.

References

External links

*
Quadruplex Park vtr formats, with a mention of W-VHS
{{High definition media Videotape VHS Products introduced in 1994 Japanese inventions

Naming

Mechanism

Use

See also

References

External links