Television (TV), sometimes shortened to tele or telly, is a telecommunication medium used for transmitting moving images in monochrome (black and white), or in color, and in two or three dimensions and sound. The term can refer to a television set, a television show, or the medium of television transmission. Television is a mass medium for advertising, entertainment, news, and sports.
Television became available in crude experimental forms in the late 1920s, but it would still be several years before the new technology would be marketed to consumers. After World War II, an improved form of black-and-white TV broadcasting became popular in the United Kingdom and United States, and television sets became commonplace in homes, businesses, and institutions. During the 1950s, television was the primary medium for influencing public opinion. In the mid-1960s, color broadcasting was introduced in the US and most other developed countries. The availability of multiple types of archival storage media such as Betamax and VHS tapes, high-capacity hard disk drives, DVDs, flash drives, high-definition Blu-ray Discs, and cloud digital video recorders has enabled viewers to watch pre-recorded material—such as movies—at home on their own time schedule. For many reasons, especially the convenience of remote retrieval, the storage of television and video programming now also occurs on the cloud (such as the video on demand service by Netflix). At the end of the first decade of the 2000s, digital television transmissions greatly increased in popularity. Another development was the move from standard-definition television (SDTV) (576i, with 576 interlaced lines of resolution and 480i) to high-definition television (HDTV), which provides a resolution that is substantially higher. HDTV may be transmitted in various formats: 1080p, 1080i and 720p. Since 2010, with the invention of smart television, Internet television has increased the availability of television programs and movies via the Internet through streaming video services such as Netflix, Amazon Video, iPlayer and Hulu.
In 2013, 79% of the world's households owned a television set. The replacement of early bulky, high-voltage cathode ray tube (CRT) screen displays with compact, energy-efficient, flat-panel alternative technologies such as LCDs (both fluorescent-backlit and LED), OLED displays, and plasma displays was a hardware revolution that began with computer monitors in the late 1990s. Most TV sets sold in the 2000s were flat-panel, mainly LEDs. Major manufacturers announced the discontinuation of CRT, DLP, plasma, and even fluorescent-backlit LCDs by the mid-2010s. In the near future, LEDs are expected to be gradually replaced by OLEDs. Also, major manufacturers have announced that they will increasingly produce smart TVs in the mid-2010s. Smart TVs with integrated Internet and Web 2.0 functions became the dominant form of television by the late 2010s.Television signals were initially distributed only as terrestrial television using high-powered radio-frequency television transmitters to broadcast the signal to individual television receivers. Alternatively television signals are distributed by coaxial cable or optical fiber, satellite systems and, since the 2000s via the Internet. Until the early 2000s, these were transmitted as analog signals, but a transition to digital television was expected to be completed worldwide by the late 2010s. A standard television set is composed of multiple internal electronic circuits, including a tuner for receiving and decoding broadcast signals. A visual display device which lacks a tuner is correctly called a video monitor rather than a television.
I was unsure where to put this; in the electrical engineering forum or the computer science forum. But since it is a compression technology decided, to put it here.
First, for background, here is an overview of the most common video compression standard in use today, H264...
My elderly parents, before they passed, would call me into the room almost every night to unbork their television because of the remote control. It seems every single remote control, and if you’re like me you have a pile of them, has the exact same problem that baffles the elderly who are...
Hi friends,
I am studying this circuit which is the first all electronic television receiver created by Dr. Farnsworth back in 1927. Triode are being employed along with some caps and coils. The design is very simple and clear, basically this receiver is a detector circuit which detects the...
I was surfing the net to get some ideas involving the Kerr electro-optic effect and noticed this Wikipedia external link.
It's page two from Television History - The First 75 Years. It has some cool old articles and pictures like these (images can be made larger in your browser):
Just...
Homework Statement
A dealer has a stock of 6 similar television sets which he rents out to customers on a monthly basis. It is known from past experience of the dealer that the monthly demand for the television sets have a Poisson distribution with mean 3.56
(i) Find the probability that in any...
Airwolf (from the T.V show Airwolf) is a Mach 1+ helicopter capable of reaching speeds up to Mach 2. For it's time, it's weapons system was pretty farfetched (had fourteen weapons systems overall, including chaffe and flares) at it's time.
I'm well aware of the limits of regular helicopters'...
from a bit of googling, i realize it's because the frame rate of the camera and the projector are different. however, i have tried recording videos with cameras of 60fps, 30fps and 15fps, and the projector is likely 60 fps. That's why I'm curious about this - which frame rate is faster (the...
Hello!
I have a PAL TV, and that means it is best for footage of 25fps and 50fps
The TV's refresh rate is 200Hz
Well, my questions are:
What happens if I play an NTSC file on the TV? (≈30fps), since it doesn't go well with 200Hz much (isn't a multiple)...
I thought about how would the TV...
I'm thinking about Cathode Ray Tube (CRTs) television sets. I'm also studying consciousness and attempting to wrap my cognition around Fourier transformations. There are electronics involved. And there is energy and power involved. However, all of it comes together to develop a visual, right...
I was reading a BBC News article about living on the cheap.
It mentioned the cost of a television license.
Tried to google and it looks like it's literal. To watch TV (own a TV)in the UK you need a license.
Does that include the "cable package" or something?
I must not understand...
One watched TV in ambient light to avoid strain on eyes. What role is ambient light playing and how can this be explained in terms of physics of photons which come from the TV and which come from ambient light.
Hi guys/gals.
Enjoying the Superbowl here on the east coast. Hope you guys are having a good evening too.
My question is how is the encoding for TVs done? I've read the NTSC link below. I didn't see how exactly the signal is created but rather more about where the different data are stored...
Do lcd televisions / monitors process component signals for each pixel in every frame? or is there like an approximation it uses? how complex is the signal with this information?
I mean like, if I were to take the video cable out of my TV, and hook it up to an oscilloscope, what sort of...
Homework Statement
Why is the length of time over which a phosphor emits light an imporant factor to consider when designing a television screen?
Homework Equations
The Attempt at a Solution
I have gone over the last three chapters in my textbook for the answer. I even drove to...
Right now I'm watching "Civilization Lost" on the H2 CHannel, and they just discussed an idea I've heard before, concerning the possibility of a nuclear fission detonation of natural origin having destroyed an African civilization.
I don't buy that. :mad:
I mean, even those of us who...
How is it possible that when one watches a color television screen, one perceives the three base colors of the pixels as if it were a mix tone of these base frequencies, proportional to the relative intensity of the different pixels? It puzzles me! Hope someone knows how this is possible.
Like they're difficult to find!
(OK, so I realize I'm going out on a limb here, considering the pounding I recently took in the "The Nobel Prize in Physics 2011 goes to Saul Perlmutter Brian Schmidt and Adam Riess" thread under General Discussion in the Lounge, but, well, I'll cast caution to...
I was watching television the other night, and I saw a commercial for a certain cable company, whose name I shall not mention. The ad took the viewer into a world of chaos: windows shattered, buildings aflame, and criminals acting with impunity. It was a scene without any hope of order or even...
Homework Statement
my textbook material on vidicon television camera is inadequate and i would like to know some web links from revered members which could provide some exhaustive coverage of vidicon. could members provide the link?
Homework Equations
The Attempt at a Solution
All of a sudden the picture on my Panasonic CRT television disappeared, but the sound remained. The most common cause of the picture disappearing is a faulty tube and the warning sign of this can be seen for some while.
So it can't be the tube. There was a funny burning type smell from the...
Television Commercials--hate 'em or love 'em
one...
I've seen the commercial for Topsy-turvy--the planter that hangs with the upside down tomato plant---
if you notice, its the same tomato plant in ALL of the scenes...
http://www.destructoid.com/watch-some-hypocrites-attack-videogames-on-british-tv-168784.phtml
For those that can't be bothered watching(!) - the video is a clip from The Alan Titchmarsh show about video-games. The discussion is about the impact violent video games have on children. The critics...
I'm bored. What is the stupidest show on television in your opinion?
Oh and anything on MTV doesn't count.
My #1 stupidest show is... hmm wlel, i need to think about this. Inside Edition makes me want to rip my eyes out sometimes...
Homework Statement
An electron is accelerated horizontally from rest in a television picture tube by a
potential difference of 25,000 V. It then passes between two horizontal plates 6.5 cm
long and 1.3 cm apart that have a potential difference of 250 V, as shown below. At
what angle θ will the...
Hello. I have recently obtained a working television flyback power supply. I would like to run a pulsed signal through it to create a power supply for a small project I am working on. In order to do this, it is necessary for me to locate the location of the primary and secondary coil pins. I am...
ive noticed several times that when I am watching tv, and my phone rings, that my ringtone will actually play through my tv speakers. does anyone know why that happens?? thanks.
http://en.wikipedia.org/wiki/Great_Beijing_Mandarin_Oriental_Hotel_fire_of_February,_2009
Can anyone explain to me why didn't this building collapse on itself after burning for 5 hours? I thought the steel would have weakened enough to allow some kind of total or partial collapse. This...
Homework Statement
What is the speed of impact of electrons with the screen of the picture tube? Answer in units of m/s.
Electrons are accelerated through a potential difference of 15500 V
Charge of electron: 1.6 x 10^-19 C
Mass of electron: 9.11 x 10^-31 kg
Energy of electrons when they hit...
I have noticed that the television makes a very high pitched noise. You almost can't tell your hearing it until it is turned off. It is kind of like the ringing of the ear in a way. Then When I turn on the DTV box, the sound becomes a little louder and changes frequency.
Does anyone know...
For years i wondered why would the US Government mandate an end to broadcast TV. And then i came across this thread and was amazed that what i read was even possible. Since I really didn't really grasp what i was reading. So i decided to post it here with the link. Hoping that some of you can...
[SOLVED] Beam Deflection in a Television Tube
Homework Statement
Each of the electrons in the beam of a television tube has a kinetic energy of 10.8 keV. The tube is oriented so that the electrons move horizontally from geomagnetic south to geomagnetic north. The vertical component of Earth's...
A pair of horizontal plates is used to deflect electrons up or down in a television set by placing a potential difference across them. The plates have length 0.04 m. and separation 0.012 m, and the right edge of the plates is 0.50 m from the screen. A potential difference of 200 V is applied...
Can X rays be produced by a television picture tube?
My attempt
It is possible that X-rays can be produced by a television picture tube or a Cathode Ray tube because by altering the CRT X- rays may be produced.
I have no idea if that is true but i think so.
Something happened that reminded me of this tonight, and I think I have finally made sense of something seen as a kid. For some odd reason it just hit me. When I was fairly young and living in the Los Angeles area, there was a test done one night on a local TV channel that was supposed to...
Hello!
I'm considering the purchase of a 100 pound LCD television. I anticipate mounting it with an articulating mounting system. The mounting system will allow the television to extend ~27 inches from the mounting wall (thereby creating a considerable torque load on the wall studs used)...
I have just realized that one purpose of movies and television shows is to kind of give the community a message of 'how to behave' in society. Obviously it must also be entertaining. The goodies always tend to win in movies which is trying to give us the message that doing 'good' is...
How does physics play a role in televisions with respect to light waves, radio waves, and sound waves. Also, if the speed of light is faster than the speed of sound, why does the picture and sound arrive at sync in a television. I just need to know a little bit about the basis of a television...
Homework Statement
A repairman fixes broken televisions. The repair time is exponentially distributed with a mean of 20 minutes. Broken television sets arrive at his shop according to a Poisson process with arrival rate 12 sets per working day. (8 hours).
(i) What is the fraction of time that...
Homework Statement
In a typical television tube, the electrons are accelerated through a potential difference of 25,000 volts. a) What speed do the electrons have when they strike the screen? And b) What is their kinetic energy in joules?Homework Equations
K_m_a_x = hf - \varphi
KE = \gamma...
The following is my own expansion on Schrodinger’s original thought experiment, but taken to another level. It is envisaged here as something that might be carried out and verified.
(Ethics demand that this should never be performed with a cat. It could easily be done with just the harmless...
If you don't remember that Simpson's episode, Homer lowers his voice and hushes semi-erotically when he says the words "secret lover," while cradling a portable television. The first time I saw this, the Freudian connection escaped me. I was too disturbed by it for the obvious reasons and didn't...
I can't decide which person I find most irritating but I've narrowed it down to two possiblities and they are both on cell phone commercials. Number one is the fat guy who has Dukes of Hazzard theme song as his ring tone and sings along to it and the second is the blond crack whore with the...
Does anyone have an idea of where I can get a 5"/9"/13" television (color) for under $75? The ones that I see one the net come with a vcr or dvd player. I just want a little tv for a good price. It does not have to be flat screen or anything.
Does anyone here remember talk a few years ago about setting up a network to connect television satallite dishes to be used for astronomy? the theory was use the dishes overnight when most people are not watching. It could provide a large view and perspective with a surface area surpassing...