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Blu-ray
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What is Blu-ray?
Blu-ray is an optical disc data-storage format often used for playing high-definition (HD) video. It is the third generation of compact disc (CD) technology, coming after audio CDs and digital video discs (DVDs).
Like CDs and DVDs, Blu-ray stores data on a plastic disc. A blue-violet laser reads the data encoded on the disc. Because Blu-ray uses a shorter wavelength laser, its spiral track is more tightly wound, allowing it to hold more information than a DVD. A single-layer Blu-ray disc holds 25 gigabytes (GB), while a dual-layer disc holds 50 GB. In comparison, a single-layer DVD holds only 4.7 GB.
In 2008, Blu-ray became the entertainment industry's preferred standard for storing HD video, and Toshiba's group stopped developing HD DVD.
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How does a Blu-ray disc store information?
A Blu-ray disc stores data using pits that form a spiral track. A blue-violet laser with a wavelength of 405 nanometres reads these pits. Because Blu-ray uses a shorter wavelength laser than DVDs, its spiral track is more tightly wound, allowing it to hold more information. A single-layer Blu-ray disc can hold 25 gigabytes, while a dual-layer disc holds 50 gigabytes. This technology emerged as a successor to DVDs, offering greater storage capacity for high-definition video.
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How is Blu-ray different from a DVD?
Blu-ray and DVD are both optical disc data-storage formats, but Blu-ray is the third generation of compact disc (CD) technology, while DVD is the second. The primary distinction lies in their storage capacity and laser technology. A single-layer Blu-ray disc can hold 25 gigabytes, whereas a single-layer DVD holds only 4.7 GB. This is because Blu-ray uses a blue-violet laser with a shorter wavelength (405 nanometres) compared to DVDs (635 or 650 nanometres), allowing for more tightly wound tracks and greater data density. Due to its increased storage capacity and ability to support high-definition video, Blu-ray became the preferred standard over HD DVD in 2008.
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What type of laser does Blu-ray technology use?
Blu-ray technology uses a blue-violet laser to read data. This laser emits light at a wavelength of 405 nanometres. The shorter wavelength allows the spiral track on the disc to be more tightly wound, which means the Blu-ray disc can hold more information than a DVD. A single-layer Blu-ray disc can hold 25 gigabytes, while a dual-layer disc holds 50 gigabytes.
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How much data can a standard Blu-ray disc hold?
A standard single-layer Blu-ray disc can hold 25 gigabytes (GB) of data, while a dual-layer disc can hold 50 GB. Blu-ray technology uses a blue-violet laser to read data encoded in pits on the disc. The shorter wavelength of the blue-violet laser allows for a more tightly wound spiral track, which increases the amount of data that can be stored compared to DVDs. A DVD can only hold 4.7 GB of data.
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What are some advantages of Blu-ray technology for movies and video games?
Blu-ray technology offers significant advantages for movies and video games because of its ability to store high-definition (HD) video.
Here are key benefits:
* High storage capacity A single-layer Blu-ray disc can hold 25 gigabytes (GB) of data, while a dual-layer disc holds 50 GB. This is much more than a DVD, which only holds 4.7 GB on a single layer.
* Better resolution Its high storage capacity makes it well-suited for motion pictures on high-definition television (HDTV) screens.
* Advanced technology Blu-ray uses a blue-violet laser with a shorter wavelength to read data, allowing for more tightly wound tracks and greater storage density compared to DVDs.Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Blu-ray, optical disc data-storage format that is most often used for playback of high-definition (HD) video.
Blu-ray represents the third generation of compact disc (CD) technology, after audio CDs and digital video discs (DVDs). In all three technologies, data is stored on a plastic disc 120 millimetres (4.75 inches) in diameter. The data is encoded in pits that form a spiral track on the disc. A blue-violet laser, emitting at a wavelength of 405 nanometres, reads the pits. Because the laser used in a Blu-ray is of a shorter wavelength than that used in DVDs (635 or 650 nanometres), the spiral track can be more tightly wound. Thus, the Blu-ray disc can hold more information than the DVD. A single-layer Blu-ray holds 25 gigabytes (GB), and a dual-layer Blu-ray (one with two layers of information, one on top of the other) holds 50 GB. By contrast, a single-layer DVD holds only 4.7 GB.
As television systems switched over to digital signaling, high-definition television (HDTV) became available, featuring much greater picture resolution (1,920 by 1,080 pixels) than traditional television (usually 720 by 480 pixels). Motion pictures were especially suited for display on wide flat-panel HDTV screens, and in 2002 two competing but incompatible technologies were presented for storing HD video on a CD-sized disc: HD DVD, proposed by Toshiba and the NEC Corporation, and Blu-ray, proposed by a group led by Sony. Both technologies employed a laser emitting light in the blue-violet end of the visible spectrum.
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With two incompatible technologies on the market, consumers were reluctant to purchase next-generation players for fear that one standard would lose out to the other and render their purchase worthless. In addition, movie studios faced a potentially expensive situation if they produced movies for the losing format, and computer and software firms were concerned about the type of disc drive that would be needed for their products. Those uncertainties created pressure to settle on a format, and in 2008 the entertainment industry accepted Blu-ray as its preferred standard. Toshiba’s group stopped development of HD DVD. By that time, doubts were being raised about how long even the new Blu-ray discs would be viable, as a growing number of movies were available for HD streaming online, and cloud computing services offered consumers huge data banks for storing all sorts of digitized data.
The doubters were correct. Blu-ray disc sales in the United States peaked in 2013, and sales of Blu-ray discs and DVDs combined fell by almost half from 2014 to 2018, with the decline attributed to competition from streaming services like Netflix and Amazon Prime Video. Even the introduction of Ultra HD 4K Blu-rays in 2016, for displays with a resolution of 3,840 by 2,160 pixels, failed to slow the decline. In 2019 Samsung announced that it would not introduce any more new Blu-ray player models in the U.S.