Objectives
After studying this chapter, you will be able to:
Explain the steps in the transmission of a television
signal.
Discuss the scanning process.
Identify circuits in both black-and-white and color
television receivers and explain their functions.
Identify the size and makeup of a television
channel.
Discuss a variety of television innovations includ-
ing video cassette recorders, remote control, and
satellite television.
List the benefits of HDTV as compared to analog
television.
Explain the difference between multicasting and
datacasting.
Discuss the compression technique of MPEG2.
Discuss the various flat-panel technologies.
Key Words and Terms
The following words and terms will become impor-
tant pieces of your electricity and electronics vocabulary.
Look for them as you read this chapter.
Television is a giant in the field of communications.
Through television, entertainment, education, informa-
tion, and advertising are available to millions of people.
And through satellite links, television can instantaneously
bring the entire world into our home or office.
This text will not address the detailed electronic
circuits involved in the production, transmission, and
reception of television signals. However, it is important for
all persons interested in the science of electronics to have
a basic knowledge of television and related information.
23.1 TELEVISION SIGNALS
Taking a picture from one location and reproducing
it in your home is a combination of several processes.
First, a television camera must record the images to be
transferred. Next, those images must be turned into radio
waves and sent out into the air, or turned into electrical
signals and transmitted through cables. Finally, the sig-
nals must be received and translated back into pictures.
Television Cameras
What looks like a solid picture is really an extremely
large number of dots. In a black-and-white picture, these
dots are varying degrees of black and white. They are
called picture elements. Look closely at a photo in a daily
newspaper and you will see that these picture elements
are clearly visible.
393
Television and
Video Display Units
active-matrix
Advanced Television
Systems Committee
(ATSC)
aspect ratio
brightness control
charged coupled device
(CCD)
datacasting
deflection yoke
electro-luminescence
enhanced definition
television (EDTV)
feedhorn
fine-tuning
focal point
frame
frame rate
geostationary orbit
high definition television
(HDTV)
liquid crystal display
(LCD)
MPEG2
multicasting
National Television
Standards Committee
(NTSC)
passive-matrix
picture element
pixel
polarized light
progressive scanning
raster
resolution
scanning
shadow mask picture tube
synchronization (sync)
pulse
thin film transistor liquid
crystal display (TFT-LCD)
tuner
ultra high frequency (UHF)
very high frequency (VHF)
video detector
video head
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