The Television, from Analog to Digital, and Somewhere in Between

How do they get those people in the television set? How are images able to be seen on our television sets? Throughout history we as a society have strived to create our world a better place to live in through technology. With some of that same technology we have given ourselves headaches, but for the most part the government has given us those headaches. The television being one of the greatest devices ever invented has many very good points and some may say they have bad points. There is a ruling from the Federal Communication Commission (FCC) that will affect the way we watch television. We have to realize that such a ruling has a high cost and implications that will affect lower income families and even middle class families. What ever you may think, we have to agree that it was only a matter of time before our government some how would interfere with it is simplicity.

As with any device, we have to make it better, we can not leave well alone. As a society do we not do that? What is so fascinating about the television is that it was not invented by a single person. Instead, it was invented by many people who were either working together or alone that contributed to the evolution of the television. In 1831 Joseph Henry's and Michael Faraday's work with electromagnetism made it possible for the era of electronic communication to begin. It took nearly 31 years later for Abbe Giovanna Caselli to invent the "pantelegraph", which made him the first person to transmit a still image over wires. These two important strives lead to the successful transformation of images into electronic signals in 1873 by two scientists named Joseph May and Willoughby Smith.

Just the meaning of the word television was not conceived until 1900, during the World's Fair in Paris. All these important points in history have created the path where we are today with this technology. April 9th, Secretary of Commerce Herbert Hoover commented, "Today we have, in a sense, the transmission of sight for the first time in the world's history. Human genius has now destroyed the impediment of distance in a new respect, and in a manner hitherto unknown." (Smith 35)

Before we go into how the television affects our everyday life, first you have to know the inner workings of the television. In order to get people to appear in the television, the images need to be turned into an electromagnetic radiation or in layman terms, radio waves. The images are instantaneous transmissions such as pictures or scenes, fixed or moving. The image is broken down into small pieces by a scanning process and then sent one line at a time. Scanning is breaking up an image into individual elements that can later be reassembled to re-create a picture. The eye of the scanner sweeps over a page of print, word by word and line by line.

The scanner generates an electrical signal at the receiver; a second scanner re-creates the image which is either done mechanically or electrically. All modern television systems utilize beams of electrons that sweep across the screens of camera tubes or receiving tubes. The advantage of scanning with an electron beam is that the beam can be moved with great speed and can scan an entire picture in a fraction of a second or faster. Each line contains hundreds of bits of the image, which is called the video signal. There are four parts of the signal:

* a series of fluctuations corresponding to the fluctuations in light intensity of the picture elements being scanned

* a series of synchronizing pulses that lock the receiver to the same scanning rate as the transmitter

* an additional series of so-called blanking pulses;

* a frequency-modulated (FM) signal carrying the sound that accompanies the image.

That video signal is then carried from one location to another either by radio waves, fiber optics or coaxial cable but the conversion process is the heart of the television. Television stations use vestigial sideband (VSB) to send the video via radio waves which is similar to amplitude-modulation (AM). The VSB filters out parts of the modulated signal that have been duplicated in order to reduce the amount of channel space (bandwidth). Television signals take up a lot of channel space which typically is around 1000 times that of audio signals, so it's important to save as much space as possible. The video signal is then received by the picture tube and translated to a picture we see on the television set. Today there are two different types of television systems: the traditional satellite television which uses low microwave frequencies that require large dishes and use FM signals for sending the video feed.

There is a big distinction between analog and digital television signals. It is especially true when it comes to purchasing them. First, what is a signal? Plain and simple, a signal is the transmission of data. We deal with signals constantly during the span of our lives. We interact with signals from music, power lines, telephones, and cellular devices. This means the use of antennas, satellites, and of course wires. In many cases, knowing how signals work will help you solve some kind of technical problem over the span of your life. (Rodriguez)

Television technology is growing rapidly. Many new television sets are now capable of handling the highest quality pictures. A digital direct-view TV will have much greater resolution than its analog counterpart. The term "digital" refers to a type of electronic signal in which the information is stored in a sequence of binary numbers, rather than in a continuously varying signal (known as an analog signal). Most digital TVs can display progressive-scan digital versatile disc (DVDs) (480p) and high definition television (HDTV) (usually 1080i) at full resolution. Analog sets cannot, they send a signal telling the television's electron gun how to "paint" lines on the screen. The problem is that the signal degrades in transmission, affecting the amount of fine detail in the image. Digital sets send this same information in bit streams (lines of data made up of ones and zeroes). The advantage is that these digital signals do not degrade, so the picture is much better on a digital set.

No matter how much money you spend on a TV, the picture will only be as good as the source signal it receives. For instance, a DVD will look better on a low-end television than an analog broadcast antenna signal will look on a high-end HDTV. That is because the quality of the digital signal sent to the analog set is far superior to the analog signal sent to the digital HDTV. Analog coaxial cable is already in place and has been used for many years