DVD recorder

A DVD recorder is an optical disc recorder that uses optical disc recording technologies to digitally record analog or digital signals onto blank writable DVD media. Such devices are available as either installable drives for computers or as standalone components for use in television studios or home theater systems. As of March 1, 2007 all new tuner-equipped television devices manufactured or imported in the United States must include an ATSC tuner. The US Federal Communications Commission (FCC) has interpreted this rule broadly, including apparatus such as computers with TV tuner cards with video capture ability, videocassette recorders and standalone DVD recorders. NTSC DVD recorders are undergoing a transformation, either adding a digital ATSC tuner or removing over-the-air broadcast television tuner capability entirely. However, these DVD recorders can still record analog audio and analog video. Standalone DVD recorders, alongside Blu-ray recorders, have been relatively scarce in the United States due largely to "restrictions on video recording" and piracy concerns. The first DVD recorders appeared on the market in 1999–2000. Originally, DVD recorders supported one of three standards: DVD-RAM, DVD-RW (using DVD-VR), and DVD+RW (using DVD+VR), none of which are directly compatible. Most current DVD drives support both the + and - standards, while few support the DVD-RAM standard, which is not directly compatible with standard DVD drives. Recording speed is generally denoted in values of X (similar to CD-ROM usage), where 1X in DVD usage is equal to 1.321 MB/s, roughly equivalent to a 9X CD-ROM. In practice, this is largely confined to computer-based DVD recorders, since standalone units generally record in real time, that is, 1X speed. Recorders use a laser (usually 650 nm red) to read and write DVDs. The reading laser is usually not stronger than 5 mW, while the writing laser is considerably more powerful. The faster the writing speed is rated, the stronger the laser.