Television set
The ubiquitous television set became the display device for the first recorded media for consumer use in the 1970s, such as Betamax, VHS; these were later succeeded by DVD.
It has been used as a display device since the first generation of home computers (e.g. Timex Sinclair 1000) and dedicated video game consoles (e.g., Atari) in the 1980s.
[1][2][3][4][5] Modern flat-panel TVs are typically capable of high-definition display (720p, 1080i, 1080p, 4K, 8K) and can also play content from a USB device.
[10] In 1926, Kenjiro Takayanagi demonstrated the first TV system that employed a cathode-ray tube (CRT) display, at Hamamatsu Industrial High School in Japan.
[11] The first commercially made electronic televisions with CRTs were manufactured by Telefunken in Germany in 1934,[13][14] followed by other makers in France (1936),[15] Britain (1936),[16] and US (1938).
[22] Early electronic television sets were large and bulky, with analog circuits made of vacuum tubes.
However, the first fully transistorized color TV set, the HMV Colourmaster Model 2700, was released in 1967 by the British Radio Corporation.
[30] Late model CRT TVs used highly integrated electronics such as a Jungle chip which performs the functions of many transistors.
[34] Lechner, F. J. Marlowe, E. O. Nester and J. Tults demonstrated the concept in 1968 with a dynamic scattering LCD that used standard discrete MOSFETs.
By the early 2010s, LCD TVs, which increasingly used LED-backlit LCDs, accounted for the overwhelming majority of television sets being manufactured.
[1][2][3][4][5] In 2014, Curved OLED TVs were released to the market, which were intended to offer improved image quality but this effect was only visible at a certain position away from the TV.
[50] Cambridge's Clive Sinclair created a mini TV in 1967 that could be held in the palm of a hand and was the world's smallest television at the time, though it never took off commercially because the design was complex.
Between January and September, approximately 38 thousand televisions with a screen size of 97 inches (250 cm) or larger were sold globally.
As of mid-2019, LCDs overwhelmingly predominate in new merchandise, but OLED displays are claiming an increasing market share as they become more affordable and DLP technology continues to offer some advantages in projection systems.
The CRT requires an evacuated glass envelope, which is rather deep (well over half of the screen size), fairly heavy, and breakable.
As a matter of radiation safety, both the face (panel) and back (funnel) were made of thick lead glass in order to reduce human exposure to harmful ionizing radiation (in the form of x-rays) produced when electrons accelerated using a high voltage (10–30 kV) strike the screen.
In Television Sets (or most computer monitors that used CRT's), the entire screen area is scanned repetitively (completing a full frame 25 or 30 times a second) in a fixed pattern called a raster.
It is also used in about 85% of digital cinema projection, and in additive manufacturing as a power source in some SLA 3D printers to cure resins into solid 3D objects.
However, in the early to mid 2000s RPTV systems made a comeback as a cheaper alternative to contemporary LCD and Plasma TVs.
They were larger and lighter than contemporary CRT TVs and had a flat screen just like LCD and Plasma, but unlike LCD and Plasma, RPTVs were often dimmer, had lower contrast ratios and viewing angles, image quality was affected by room lighting and suffered when compared with direct view CRTs,[70] and were still bulky like CRTs.
These TVs worked by having a DLP, LCoS or LCD projector at the bottom of the unit, and using a mirror to project the image onto a screen.
They are called "plasma" displays because the technology utilizes small cells containing electrically charged ionized gases, or what are in essence chambers more commonly known as fluorescent lamps.
[73] In 1997, Philips introduced at CES and CeBIT the first large (42-inch or 110-centimetre) commercially available flat-panel TV, using Fujitsu plasma displays.
LCD TVs quickly displaced the only major competitors in the large-screen market, the plasma display panel and rear-projection television.
Adding mobile ions to an OLED creates a light-emitting electrochemical cell or LEC, which has a slightly different mode of operation.
Active-matrix OLEDs (AMOLED) require a thin-film transistor backplane to switch each individual pixel on or off, but allow for higher resolution and larger display sizes.
While most televisions are designed for consumers in the household, there are several markets that demand variations including hospitality, healthcare, and other commercial settings.
Other common software features include volume limiting, customizable power-on splash image, and channel hiding.
The set back box may offer channel lists, pay per view, video on demand, and casting from a smart phone or tablet.
Challenges with recycling television sets include proper HAZMAT disposal, landfill pollution, and illegal international trade.
