Chapter 23 Television and Video Display Units 419
superior to the VHS system, the VHS system became the
designated standard because of its convenience.
Review Questions for Section 23.4
1. What three things are needed to have a complete
high definition television system?
2. What is multicasting?
3. What is datacasting?
4. What does the acronym ATSC represent?
5. What does the acronym NTSC represent?
6. What do the lowercase letters i and p represent in
association with frame rates?
7. What are the two common display formats for
HDTV?
8. What does the 5.1 channel surround sound system
consist of?
9. How many pixels are required for each color dis-
play’s pixel area?
10. What are the two classifications of LCD displays
based upon the number of transistors in relation to
the number of points in the image?
11. What does the acronym DMD represent?
Summary
1. A television picture is produced by scanning an
image captured from a television camera onto a
cathode ray tube.
2. Scanning is the point-to-point examination of a
picture.
3. The scanning system used in the United States is
the interlace system. It consists of 525 scanning
lines. Scanning starts at the top left-hand corner of
the picture. It scans from left to right on the odd
numbered lines and then scans the even numbered
lines. All of this takes place 30 times per second.
4. Black-and-white signals are made by a single color
picture tube. Color signals are made by a three
color (red, blue, and green) picture tube.
5. The bandwidth of a TV signal is 6 megahertz. The
VHF band covers channels 2 through 13. The UHF
band covers channels 14 through 83.
6. Video cassette recorders are used for recording and
playback of magnetic tapes.
7. The image on a large-screen TV is made by pro-
jecting three color images onto a screen.
8. Satellite TV is used for communication worldwide
through the use of satellites that orbit the earth in a
geostationary (synchronous) position.
9. Traditional analog television uses vacuum tube
imaging to capture images, while HDTV uses CCD
cameras to capture images and convert them to dig-
ital information.
10. A digital camera uses a charged coupled device
(CCD) to capture an image and convert it into digi-
tal signals that can be stored or transmitted.
11. A pixel is a single color element of a color pixel area.
12. HDTV is associated with display formats 720p and
1080i.
13. MPEG2 is the most commonly used video com-
pression standard for HDTV.
14. Dolby surround sound consists of 5.1 channels.
15. The most popular LCD technology for high-quality
color images is the TFT-LCD.
Test Your Knowledge
Please do not write in the text. Place your answers on
a separate sheet of paper.
1. The dots that make up a picture are called
__________ __________.
2. Briefly explain the interlace scanning system.
3. What causes an electron beam to move from left to
right?
4. The speed of an electron stream from an electron
gun is increased by:
a. grids.
b. target plates.
c. scanning.
d. None of the above.
5. A composite video signal contains the:
a. video information.
b. sound information.
c. Both of the above.
d. None of the above.
6. The __________ __________ __________ is used
to produce images in most televisions.
7. What are the three colors used to produce a color
TV image?
8. What is the purpose of having more than two heads
on a VCR?
9. _____ allows for two to four channels to be broad-
cast in the same single-channel bandwidth.
10. To be considered a complete HDTV system, three
main components are required: a digital _____,
digital _____, and a _____ _____ capable of pro-
ducing images at the high definition TV resolution.
11. The _____ _____ _____ _____ developed stan-
dards for digital television broadcasting and
receivers.