Television is the offspring of three media-theater, film, and radio.
Numerous technical advances include programmable television, unlimited
channel access, stereo sound, vivid color, and video cassette and computer
hook-up. The basic theory remains focused on the cathode-ray tube (CRT).
Television and video cameras detect and digitally convert light rays reflected
from a scene or subject into electrical impulses. These cameras use change
coupled device (CCD) technology to perform this conversion. Microphones
pick up and transmit sound as electrical impulses. These electrical impulses
are simultaneously sent to a transmitter or recorded on tape. To view the
program, the transmitter sends a signal to a television set that acts as a
receiver for the signal. Inside the receiver, the signals are separated into
impulses of video and audio. The video and audio circuits change the signals
into pictures on the face of the CRT tube and sound from the loudspeakers.
Figure 3-1 shows a pictorial diagram of the concept of television.
Figure 3-1. The concept of television.
Continued on next page