The invention of television itself is, of course, the biggest innovation in TV broadcasting. Without that, we would still be huddling around the radio for our in-home entertainment. Or reading, playing outside or living at the movie theater, perhaps. It's almost hard to imagine life without TV. Over the course of the 20th century, it grew from something that didn't exist to something in nearly every U.S. household, watched by most people for several hours a day.
Television was actually a 19th-century concept that came to fruition in the 20th century. Scientists were working on it in the 1870s, and the word "television" is thought to have been coined by Russian scientist Constantin Perskyi at the 1900 World's Fair in Paris. Some of the work that led to television was actually intended for the creation of the video phone (which was ultimately invented, but didn't take off in quite the same way).
The ability to instantly beam visual as well as audio information into people's homes has had a profound impact on society. Many believe it swayed the vote in the 1960 election between John F. Kennedy and Richard Nixon after the first televised presidential debates, and it has undeniably played a major role in politics ever since. Millions were inspired by watching man set foot on the moon in 1969. Multitudes heard Walter Cronkite say, "And that's the way it is," after feeding us our nightly news, and many of us grew up learning our letters and numbers from "Sesame Street."
Television has been bringing us entertainment, news and educational content for decades. But there have been some major innovations along the way, a few of which have drastically altered the quality of our viewing and the quantity available to us. Here are some of the most important.
Radio frequencies (RF) in the electromagnetic spectrum were first allocated by the Federal Radio Commission, established by the Radio Act of 1927 to regulate all wireless communications. In 1934, the Communications Act established a new regulatory agency in its place called the Federal Communications Commission (FCC), which handled regulation of radio, telephone and other communications methods, including assignment of bandwidths. This was deemed necessary to make communications available nationwide, to prevent interference between stations and to make acquisition of the frequencies equitable.
In 1941, the FCC set aside portions of the spectrum for television. It allowed 6 MHz for each channel, and this 6 MHz was to carry both video and audio signals. This was the same year that the National Television Standards Committee (NTSC) developed standards for black-and-white analog TV transmissions in the U.S. Prior to 1952, VHF channels two through 13 were made available. In 1952, the FCC opened up 70 new channels for television, 14 through 83, known as the UHF channels.
The FCC regulates non-federal use, which includes use by local, state and private entities, and the National Telecommunications and Information Administration (NTIA) regulates federal spectrum use (for such entities as the military and the FAA). As of February 2013, frequency bands between 9 KHz and 275 GHz have been allocated to various parties. These allocations include far more than television, for instance radio, telephone and wireless services, as well as emergency services. Unlicensed portions of the bandwidth have been set aside for things like garage door openers, remote controls and WiFi. In 2009, most of the bands formerly assigned to analog television were freed for other uses by the government-mandated analog-to-digital conversion.
The original television systems were mechanical rather than electronic. They produced images by shining light through a rotating metal disc with holes in it onto a photocell -- this converted an image into pulses of electrical energy that varied by shading. The electrical pulses were sent via wire or radio waves to a bulb in a home set that shone through a similar disc spinning at the same speed. The more holes and the faster the rotation, the sharper the image. But it could only spin so fast and the resolution was pretty low. This wasn't the method that took hold.
TV as we know it was in part invented by a self-taught 15-year-old farm boy -- Philo Farnsworth -- who learned about electronics through technical journals that were left behind by a prior occupant of his family's home. He intuitively knew that the mechanical method wasn't the best way, and he started designing a method to generate and transmit rows of light and dark points to paint a picture onto a screen using electrons. He bounced his ideas off of his high school chemistry teacher, Justin Tolman.
His designs and obvious genius earned him the life savings of a couple of investors, and around the age of 20, he developed and patented a camera tube that took in images through a lens and focused them onto a photosensitive cesium oxide plate, which threw off electrons when struck by light. The electrons were captured and transmitted to a receiver. He dubbed it the Image Dissector.
But Farnsworth also caught the attention of the head of RCA (Radio Corporation of America), David Sarnoff, who had engineer Vladimir Zworykin working on electronic television, as well. Farnsworth, hoping for a licensing deal with RCA, let Zworykin have access to his lab for a few days where he was able to study the Image Dissector. He was impressed with the device, and some of its design ultimately got worked into RCA TVs.
Sarnoff offered to buy Farnsworth's company, but Farnsworth refused. Rather than pay royalties, RCA claimed that Zworykin had actually invented the first electronic television. Zworykin had filed for an earlier patent on his Iconoscope, which used a slightly different method for capturing images electronically, and had come up with a better receiver, but they couldn't prove that he had created a working model before Farnsworth. RCA kept Farnsworth in litigation for years and attempted to drive him out of business, but the fact that Farnsworth had built and demonstrated his electronic TV, and that his former teacher Tolman produced a sketch Farnsworth had made of his designs in high school, helped him win the patent battle in the mid-1930s. Toward the end of the 1930s, RCA agreed to pay royalties, but shortly thereafter, the U.S. government put a moratorium on television production due to WWII manufacturing material restrictions. By the time the war was over, his patents were nearly expired. He abandoned television, but his work contributed to such things as radar, baby incubators, telescopes and the electron microscope.
The switch from black and white to color was a major step toward realistic visuals. Just as with TV itself, a mechanical method for generating color was developed first. It involved a red, blue and green wheel spinning in front of the cathode ray tube that beamed images to the screen. Then, a more complicated but better electronic method was introduced. With black-and-white, variations in voltage affected how much light was beamed to each part of the screen, basically painting an image onto the screen with light. With color, this was still true, but instead of one beam of electrons there were three, each hitting either a red, blue or green spot at each point on the screen. These color spots were used to paint the picture. Standards for color analog TV transmission were set by the NTSC in 1953.
As with every jump in technology, early color TVs were extremely expensive (over $7000 in today's dollars). To play both black-and-white and color broadcasts required two sets of circuits. There also weren't many compatible broadcasts early on, but by the late 1960s, most shows were broadcast in color. Many people waited to adopt color TVs until their favorite shows were offered in the format. By the early 1970s, color TVs were owned by about half of U.S. homes.
Now cathode ray tubes have been replaced by alternate methods of getting light and color to the screen. Liquid crystal displays (LCD) use electrical charges to change the opacity of liquid in the screen to affect shade, and backlighting passed through colored filters produces color. LED TVs are LCDs that use light emitting diodes to light the screen. Plasma TVs produce light and color by electrifying gases between plates of glass. All use different methods to get the light and color onto the screen, but the general principle of drawing the image to the screen with colored dots is the same.
For decades, we happily ran with analog TV signals and receivers, but the advent of digital changed this. Digital has higher resolution, is less prone to interference and uses power more efficiently. Analog TV receives fluctuating levels of electrons that are converted into an image, and whatever is received by the box is displayed by the TV in real time. This can include things like white noise caused by interference. Unlike an analog TV, a digital TV has memory, so it can delay displaying to the screen while handling errors and filtering to weed out imperfections.
With digital, image and audio signals are sent as octal (base-8) or hexadecimal (base-16) packets of data. They are most often compressed using the MPEG-2 standard (Moving Picture Experts Group), although some broadcasts use the newer and more efficient MPEG-4 compression. This compressed data is decoded by the receiving TV. The equal-sized packets of data (as opposed to the varying analog signal) also make digital more energy efficient.
Digital TV supports Dolby 5.1 channel audio (provided you have a sound system that can deliver it), so it is both a visual and an audio improvement over analog. NTSC set the analog TV standards, but digital TV standards are set by the Advanced Television Systems Committee (ATSC).
The FCC mandated a switch of broadcast television from analog to digital in order to reclaim the analog RF spectrum for other uses. It was planned for either 2006 or when 85 percent of households in the stations' markets could receive digital signals. The mandate for full-powered stations to switch over was eventually set for February 2009 and then delayed until June 12, 2009. This freed up 108 MHz of the UHF spectrum at the 698 to 806 MHz bands, which can now be used for other purposes, including wireless broadband. A good bit of it was auctioned off to private companies; 24 MHz was set aside for public safety uses.
To help prevent people from losing access to television during the switchover, the U.S. government funded a coupon program that gave qualified applicants $40 vouchers to buy analog-to-digital converter boxes for their existing TVs. It also provided some funding for public education on the subject. So now, most everyone is watching digital transmissions, even if they still own old analog TVs. There are some low-powered broadcast (LPTV) stations that were exempt from the initial deadline. These are mainly small local stations that provide community-oriented broadcasts. Their deadline for terminating analog transmission is Sept. 1, 2015. Once that's done, there will be no more analog television broadcasts in the U.S.
An alternative method to broadcasting television over the airwaves carries TV signals over insulated copper coaxial cable into stations and homes. There were experimental coaxial lines as early as the 1930s, but by the 1940s, some regular lines had been laid. They were used for phone and television, and they were ideal for getting TV out to rural areas that were hard to reach via broadcast towers. Early coax could only carry one television program -- or 480 phone conversations -- at a time, but by the 1970s, those numbers reached 200 programs and 132,000 phone calls [source: FCC]. Also in the 1970s, fiber optic cable made of plastic or glass was invented that carried much more data at a faster rate than copper. Both are used now to provide consumers with ever-increasing cable, phone and Internet bandwidth.
And from this technology, the multichannel video programming distributors (MVPD) that bring millions of U.S. homes their television via this method took their name: cable TV. This incarnation of cable led to an incredible boom in the amount of available television content. It's a pay service that offers far more channel choices than the traditional broadcast networks, and the number of channels just seems to grow and grow. This has changed our viewing habits drastically. In its early days, cable TV was relatively free from commercials, but now most channels have morphed into something more similar to the traditional networks. There are premium and mostly commercial-free channels that you can get for additional subscription fees.
As of the third quarter of 2011, roughly 90 percent of households that watched TV got it through a subscription to either cable or its phone company and satellite competitors [source: Nielsen]. Relatively few relied solely on broadcast TV anymore.
Satellite was actually theorized by author and radar engineer Arthur C. Clark in 1945. The idea became a reality in the early 1960s, and it gave us the ability to nearly instantly see events happening anywhere on the globe rather than having to wait for film or tapes to reach broadcast stations.
The first communications satellite, Echo 1, was aptly named. It was a metallic balloon, 1,000 miles (1,609 kilometers) above the Earth, off of which signals could be reflected to other spots on the globe. The first active telecommunication satellite was Telstar 1, which launched in 1961 into low earth orbit, and allowed for TV, phone and fax delivery. With Telstar and the communications satellites that followed, worldwide instant televisual broadcasting became possible.
An early (and famous) demonstration of this was HBO's showing of a boxing heavyweight championship fight between Joe Frazier and Muhamad Ali called "The Thrilla from Manila," which was broadcast live to subscribers.
Satellite was first used to broadcast from locations to broadcast stations, which would then send the transmissions out to homes via traditional broadcast television channels. PBS even started broadcasting all its programming via satellite in 1978. But like cable, its name can mean the subscription service after which it is named now, too.
A breakthrough at Japan's NHK broadcasting service by engineer Yoshihiro Konishi allowed for a significant decrease in power output and increase in sensitivity of terrestrial satellite antennas, which led to satellite services such as Dish Network and DirectTV becoming competitors of broadcast and cable TV. Satellite can be broadcast over a much wider area than terrestrial towers, and became a method of getting reception, and more channels, in rural areas where cable lines had not been laid. At first, it was far more expensive than cable, but now it's comparably priced, so networks and individual consumers can get their programming from space.
The introduction of high-definition television (HDTV) ushered in an era of much better looking visuals than what we had before. It's a subset of digital TV, and as such, the standards are set by the ATSC.
For comparison, the NTSC standard for analog dictated 525 interlaced lines per screen, although only 480 were actually visible due to a synchronization gap between frames. Standard-definition television (SDTV), even digital ATSC standard, still has 480 interlaced lines. Interlaced means that the odd-numbered lines are drawn from left to right and top to bottom on the screen, and then the even numbered lines are similarly drawn down the screen, until one entire frame has been drawn. There is also enhanced-definition television (EDTV), which displays 480 progressive lines rather than interlaced. Progressive means that each line is drawn sequentially from top to bottom, which makes for a smoother picture, especially during action scenes.
But high-definition television (HDTV) blows these out of the water in terms of picture quality by upping the resolution. Japanese National Broadcasting demonstrated an HDTV system in 1981 that had 1125 lines per screen, more than double that of SDTV. But now, the most common levels of HDTV are 720p, 1080i and 1080p. HDTVs have either 720 or 1080 horizontal lines per screen. The aspect ratio was also changed from the 4:3 of SDTV to the 16:9 of most motion pictures. So 720p has a resolution of 720 by 1280 pixels, and 1080i and p have resolutions of 1080 by 1920 pixels. The "p"' and "i" stand for progressive or interlaced. While progressive is better for motion, interlaced can make static scenes appear to have higher resolution. Things like levels of compression can affect picture quality, but HDTV's images are by and large more crisp, clear and realistic than those from the TVs of yore. Upon their inception, there wasn't much content, but now there are lots of HD broadcasts -- mostly in 720p or 1080i -- as well as Internet content. And Blu-ray (and the now-defunct HD-TV) DVDs are 1080. It's also really hard to find a TV that isn't HDTV in stores.
If that's not enough resolution for you, Ultra-high definition TV (Ultra HD) may be the next big thing. As of early 2013, the two available levels are 3840 by 2160 pixels (sometimes called 4K) and 7680 by 4320 pixels. Both represent a much larger jump in resolution than SDTV to HDTV. As was the case with HDTV, there is little viewing content for them, but that's likely to change over time. They can also be used to view scaled and converted 1080p HDTV content until more is available. But Ultra HD sets are in the $20,000 to $25,000 price range as of spring of 2013, so aren't likely to be widely adopted for a while.
The glowing hockey puck, yellow first-and-ten line and virtual ads in football and other sporting events may all sound kind of narrow in scope (not affecting all of television), but they are breakthrough technologies that took a ton of technological know-how. The glowing puck was introduced first by Fox in 1996 during the NHL All-Star Game. Sensors were put on the cameras and throughout the arena, and the hockey puck transmitted signals so that the puck could be tracked in real time. A glow was superimposed for home viewers to help them follow it, and when the puck moved, a directional streak in blue or red appeared on screen to show the path it took. Though a technological marvel that took lots of money and tons of computing power -- and engineering know-how to pull off -- it was widely panned by fans of the sport. The furor over the technology seemed to up the ratings, but the glowing puck was discontinued within a few years.
The similar first-and-ten, aka "yellow line" -- introduced by ESPN in 1998 and developed by Sportvision -- was much better received, perhaps because it solved a real problem and was more unobtrusive. It even won an Emmy. Home television viewing audiences had trouble discerning the first-and-ten line, which was marked by poles held on the edges of the field. The technology's ability to "paint" the line on multiple shades of green grass, while excluding the colors of the teams' uniforms, make it really look like something painted on the ground that the players are stepping over. As of 2003, it was added to Skycam video so that replays could also have the line. The first-and-ten line is still in use today at ESPN and has spread to other networks in various forms.
Similar technology is also used to impose virtual advertisements on the fields and other parts of the sports arena (but not on people, as this is forbidden).
Before the invention of magnetic videotape, the only way to preserve a live broadcast for posterity, or re-airing to areas outside of antenna reach, was the creation of a kinescope. These were simply films taken of a monitor playing a live broadcast, and they were of poor quality. In the early to mid-1950s, several companies were working on better TV recording methods. Bing Crosby Enterprises, RCA and a company called Ampex all came up with working methods. The latter had the best quality, so Ampex machines, created in 1956, became the standard. The invention of videotape recording technology not only allowed for a much better method of preserving TV programs for archiving or re-airing, but eliminated the necessity for shows to air live at all. Programs could be delayed for better-timed viewing in different time zones, and content could be taped outside of broadcast studios more easily.
Production of TV on film was possible as well, and was done to some extent, notably starting with "I Love Lucy," but film production was slower and more costly than tape. Early videotape recorders were too large for easy portability, but as they became smaller, they became a practical replacement for film in the news industry. Video also made instant replay possible during sporting and news broadcasts.
In the mid-1970s, videotape also made its way into our homes in the form of video cassette recorders (VCR) and VHS and Betamax tapes. These were two competing formats put out by JVC and Sony, respectively. VHS won the battle and became the in-home VCR standard. These players and tapes freed viewers from having to be home for broadcasts, just as the early introduction of tape freed networks from certain filming locations. It also gave us the ability to buy or rent movies (and later TV shows) to watch at will. The availability of increasingly smaller and inexpensive video cameras has also made it possible for people to make their own video content, more cheaply and easily than on film.
As is always the way, videotape and VCRs have made way for better technologies, such as digital video recorders (DVRs) that allow you to save programs to a hard drive, and DVDs, which can be used to make recordings of programs that will last much longer than magnetic tape. But videotape was the granddaddy of mainstream in-home recording.
The Internet has given us yet another method for finding and consuming audiovisual entertainment. The availability of fast broadband Internet service in the home (much of it via cable TV, and some via phone and satellite companies) has enabled the Internet to become a competitor of the more traditional television networks and services. You can even drop your cable subscription and still find tons of things to watch, although this often requires paying for new (albeit cheaper) subscriptions to services like Netflix, Hulu Plus and Amazon Prime. Still, there are free venues like Crackle and YouTube.
Internet content can be watched on your computer monitor, or your smartphone, but there are also tons of set-top boxes that can stream it to your TV, such as the Roku box, most gaming systems and many DVD players. Traditional providers are also jumping on the online bandwagon by providing streaming options to subscribers, like Comcast's TV Anywhere or HBO's HBO Go, which require a cable subscription but allow you to watch otherwise inaccessible programming via computer and mobile devices. And traditional networks like ABC often let you stream their shows online, as well.
There is a growing trend of people cutting off cable and satellite in favor of the Internet, but the vast majority of U.S. households still subscribe to a multichannel video programming distributor (MVPD) service. If you are addicted to staying current on the latest programming, it's not necessarily possible to cut the cord just yet without losing access to at least some of your favorite shows. But even if you continue to subscribe to more traditional TV, the Internet can also be used to greatly increase the amount of content available to you. Online services offer far more on-demand movies and older seasons of shows than you generally find in cable's video on-demand offerings.
As of early 2013, cable and satellite providers have the right to carry certain channels and the responsibility to carry others, and most Internet providers are blocked from providing a lot of their instantaneous content. But the FCC is considering changes to the definition of Multichannel Video Program Distributor that might possibly allow Internet-based TV content distributors to carry more channels. Such a change could result in many more viable choices than we currently have.
Online providers are getting creative, too. While previously, they simply licensed and made available existing TV and movie offerings, they are now starting to fund and create their own content, such as the upcoming "Arrested Development" season 4. It was a critically acclaimed Fox show that was canceled after three seasons, but Netflix decided to order more episodes for their streaming service.
Though most of the money and content is still in the major networks and cable/satellite providers, there may soon be a new sheriff in town. However, you might still be tethered to cable or satellite to provide the super high-speed Internet you need to view this content.
Check out our other countdowns of fascinating inventions from throughout history.