But with the success of gaming consoles and PCs, CD-I did not have the change of succeeding. Picture quality was also excellent, thanks to digital video with more than 16 million colors.ĬD-i was not just promoted by Philips shortly after the introduction some 850 companies around the world were involved: product developers, studios, publishers, player manufacturers, TV producers, advertising and PR agencies and many more. Or any combination of these, as the CD-i titles showed. It was expected to have a great future in areas like learning and entertainment, and Philips launched more than 30 titles when the system was introduced, while by the end of 1991 at least 50 titles were available in the USA.Like a standard CD, a CD-i disc had a capacity of 650 MB, allowing the storage of around 7,000 photos, 72 minutes of animation or 19 hours of speech. In 1992 the CD-i was extended by Full Motion Video. This means that users could ‘communicate’ with a CD-i player and the software on the discs. Launched in 1991, the CD-i combined CD sound with video, text, animation and interactivity. By 2000 the roles of CD Video and LaserDisc were taken over by DVD. 20 and 30 cm CD Video discs were also introduced, with playing times of 40 to 120 minutes. Philips intended these discs to be an ideal carrier for video clips. The 12 cm discs were yellow to distinguish them from the silver audio CDs. It contained up to 5 minutes of (analogue) video (like LaserDisc) plus up to 20 minutes of CD digital audio, which could be played on any CD player. The 12 cm 'CD with video' was referred to as 'CDV'. Three discs sizes - 12, 20 and 30 cm - were developed. To make optical discs into a video medium, the joint license holders Philips en Sony announced the development of a CD with a video capability in 1987, under the name ‘CD Video’. But in Europe there was not so much interest. Launched in 1972 as VLP, the ‘LaserDisc’ became popular mainly in Japan and the USA among movie enthusiasts and - especially in Japan - lovers of Karaoke. This is why it is now universally used to store computer software and data. A CD-ROM allows fast data access and has a very high reliability. Like the audio CD the disc has a diameter of 12 cm and a storage capacity of 650 to 700 MB - equivalent to 450 floppy disks or more than 250,000 typed A4 pages. Which is why the CD-ROM (Read Only Memory) was developed and launched around 1985. However, few manufacturers offered CD Graphics players with the required graphic decoder, and hardly any CD Graphics discs were issued, so this feature never became a success.ĭigital audio is stored on a CD in almost the same way as computer data. This is not a new development, but one of the special ‘features’ that were included when the CD was introduced. An 8 cm CD-R has a capacity of 156 MB, or approximately 3 hours of music in MP3 format.ĬD Graphics makes it possible to store song lyrics and other information on a CD, which can be displayed on a TV screen when a disc is played. These ‘audio singles have proved to be less popular than expected, although they are being increasingly used in CD-R (CD-Recordable) form as a low-cost way to store MP3 music files. Almost all today’s CD players can play these 8 cm discs. The 8 cm ‘CD single’ was launched to take over the ‘singles’ function, with a maximum playing time of around 20 minutes and the same sound quality as a normal 12 cm CD. There were also 17 cm ‘EP’ (Extended Play) discs with a playing time of 6 to 8 minutes. These were mainly popular with young people who wanted to buy ‘hits’ at a reasonably attractive price. In the time of gramophone records, there were not only 30 cm (12 inch) LPs, but also 17 cm (7 inch) ‘singles’ with a playing time of 3 to 4 minutes on each side. The frequency response of a CD is flat within ☐.5 dB from 5 Hz to 20 kHz, with a signal-to-noise ratio of better than 90 dB. This is usually 1.2 m/s, corresponding to a theoretical maximum playing time of 74 minutes. The speed reduces as the laser moves towards the outside of the disc to keep the linear read-out speed constant. at the outside (the disc is read from the inside to the outside). at the inside of the disc to around 200 r.p.m. A CD is 1.2 mm thick and rotates at a speed that varies between around 500 r.p.m.
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