Shaped CD
Encyclopedia
A shaped CD is a non-circular compact disc
. Examples include business card CDs, CDs in the shape of a star, a map of a country, and more. These disks are usually made for marketing purposes and are properly read by most CD-ROM drives (and audio CD players, although custom-shaped CDs tend to contain less data). There are many companies that sell CDs with custom shapes.
Unlike Mini CD
s, which are smaller, but still circular versions of normal CDs, custom CDs can be any number of shapes, even more complicated shapes like gears with dozens of teeth, but are generally smooth and with rounded edges, such as ovals or rounded rectangles. A logo can be printed on a shaped CD, in the same way common audio CDs and CD-ROMs are labeled.
Shaped CDs are produced in one of two ways. A special mold can be made and used to "stamp" CDs (or DVDs) as part of the precision injection molding process that is used to make CDs and DVDs. Because of the initial cost involved in setting up this process, it is usually used for mass production. For the same reason, this is generally restricted to the production of read only CDs and DVDs (CD-rom or DVD-rom). Recordable CDs and DVDs (CD-r or DVD-r or DVD+r) are not generally available except in standard shapes including rectangular. The second method to produce a shaped CD or DVD is to produce a normal CD-rom or DVD-rom and cut it to the desired shape. This method works only for CD-rom. It will not work for CD-r because the plastic used to produce CD-r tends to splinter when cut. It is important that two criteria be met for shaped disk to function properly. First, the shape must be balanced to avoid problems when it begins to spin. Second at least three points of the outer edge must touch either the outer 12 cm diameter rim of the players tray where standard size discs fit or the inner rim where 8 cm diameter mini discs fit.
Data can only be recorded on sections of a Shaped CD that form uninterrupted circular tracks. Other parts of the shape are purely decorative - but are still often finished to the same appearance as a CD. They appear silver and reflective on the data side of the CD, even though they contain no actual valid bytes and cannot be read.
released a CD single entitled "This Here Giraffe" on the world's first ever star-shaped CD. It was in the shape of an 8-pointed star.
Business card CDs or shaped CDs can hold any type of data and can usually store anywhere from 40MB to 100MB of information. These CDs may be used for promotional pieces for business, music or many other uses.
discs with an offset center of mass
may also cause damaging vibration if played in computer CD drives, which can operate at a much higher rotational velocity than stand-alone audio CD players. Some irregularly shaped discs work with tray loading CD drives if they include a circular ridge on their underside that centers them on the part of the tray designed to hold 80 mm CDs, if the tray has such a feature.
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...
. Examples include business card CDs, CDs in the shape of a star, a map of a country, and more. These disks are usually made for marketing purposes and are properly read by most CD-ROM drives (and audio CD players, although custom-shaped CDs tend to contain less data). There are many companies that sell CDs with custom shapes.
Unlike Mini CD
Mini CD
Mini CDs, or “pocket CDs” are CDs with a smaller diameter and one third the capacity.-Formats:Amongst the various formats are the* Mini CD single, a small disc. The format is mainly used for audio CD singles in certain regions , much like the old vinyl single...
s, which are smaller, but still circular versions of normal CDs, custom CDs can be any number of shapes, even more complicated shapes like gears with dozens of teeth, but are generally smooth and with rounded edges, such as ovals or rounded rectangles. A logo can be printed on a shaped CD, in the same way common audio CDs and CD-ROMs are labeled.
Shaped CDs are produced in one of two ways. A special mold can be made and used to "stamp" CDs (or DVDs) as part of the precision injection molding process that is used to make CDs and DVDs. Because of the initial cost involved in setting up this process, it is usually used for mass production. For the same reason, this is generally restricted to the production of read only CDs and DVDs (CD-rom or DVD-rom). Recordable CDs and DVDs (CD-r or DVD-r or DVD+r) are not generally available except in standard shapes including rectangular. The second method to produce a shaped CD or DVD is to produce a normal CD-rom or DVD-rom and cut it to the desired shape. This method works only for CD-rom. It will not work for CD-r because the plastic used to produce CD-r tends to splinter when cut. It is important that two criteria be met for shaped disk to function properly. First, the shape must be balanced to avoid problems when it begins to spin. Second at least three points of the outer edge must touch either the outer 12 cm diameter rim of the players tray where standard size discs fit or the inner rim where 8 cm diameter mini discs fit.
Data can only be recorded on sections of a Shaped CD that form uninterrupted circular tracks. Other parts of the shape are purely decorative - but are still often finished to the same appearance as a CD. They appear silver and reflective on the data side of the CD, even though they contain no actual valid bytes and cannot be read.
History
The Flaming LipsThe Flaming Lips
The Flaming Lips are an American alternative rock band, formed in Oklahoma City, Oklahoma in 1983.Melodically, their sound contains lush, multi-layered, psychedelic rock arrangements, but lyrically their compositions show elements of space rock, including unusual song and album titles—such as "What...
released a CD single entitled "This Here Giraffe" on the world's first ever star-shaped CD. It was in the shape of an 8-pointed star.
Compatibility
Shaped CDs are not compatible with all CD players. They work with most machines where the disc is inserted by manually clipping it onto a spindle (the mechanism in virtually all portable CD players), but may not work in drives that load the disc from a tray, or those that pull the disc into a slot. They can even get stuck in these players.Business card CDs or shaped CDs can hold any type of data and can usually store anywhere from 40MB to 100MB of information. These CDs may be used for promotional pieces for business, music or many other uses.
Asymmetric discs
Irregularly shaped, non-rotationally-symmetricRotational symmetry
Generally speaking, an object with rotational symmetry is an object that looks the same after a certain amount of rotation. An object may have more than one rotational symmetry; for instance, if reflections or turning it over are not counted, the triskelion appearing on the Isle of Man's flag has...
discs with an offset center of mass
Center of mass
In physics, the center of mass or barycenter of a system is the average location of all of its mass. In the case of a rigid body, the position of the center of mass is fixed in relation to the body...
may also cause damaging vibration if played in computer CD drives, which can operate at a much higher rotational velocity than stand-alone audio CD players. Some irregularly shaped discs work with tray loading CD drives if they include a circular ridge on their underside that centers them on the part of the tray designed to hold 80 mm CDs, if the tray has such a feature.