- What
is Digital Television or DTV?
Digital TVs are televisions that can receive
and display digital television broadcasts sent using any one of
eighteen digital signaling methods. Consumer Electronics Association
(CEA) classifies digital televisions in three broad categories:
HDTV (High Definition TV), EDTV (Enhanced Digital TV), and SDTV
(Standard Definition TV).
- How is
my current television different from DTVs?
The TV you watch today is based on an analog
system developed over 50 years ago. Due to the analog nature of
the system, it is likely that your current TV was designed to
receive analog signals only. You can receive and display digital
broadcasts on your existing analog TV through a digital-to-analog
converter box; however, its quality is compromised by the display
limitations of the analog TV.
- What
is the difference between HDTV, EDTV, and SDTV?
HDTV,
EDTV, and SDTV reference the ability of a digital television to
re-display various digital TV broadcasts in its original format.
Digital TV broadcasts can be transmitted using any one of eighteen
resolution-formats (See#4); however, digital televisions differ
in their ability to redisplay the image, especially when a high-definition
image is received.
HDTVs can receive all 18 formats and re-display high-definition
images using 540 lines (1080 lines interlaced) or 720 lines (progressive
scanning method) without down converting.
EDTVs can receive all 18 formats including high-definition broadcasts
and all 18 formats are re-displayed at 480 lines using progressive
scan method. This method reduces flicker; however, picture quality
may not necessarily outperform 480 interlaced when viewed at normal
viewing distances.
SDTVs can receive all 18 formats including high-definition broadcasts
and all 18 formats are re-displayed at 480 lines using interlacing
(same resolution as current analog TVs). This means that high-definition
broadcasts are down-converted in order to display the image at
480 lines.
- What
are the 18 formats of ATSC standard?
There are 18 digital television formats
prescribed by the Advanced Televisions Systems Committee. Six
are considered HDTV formats (1080p, 1080i, and 720p). Each format
has a different combination of screen resolution, scan mode, frame
rate, and aspect ratio requirements.
ATSC Picture Display Format
| |
Format
|
Vertical
Scan Lines
|
Horizontal
Pixels
|
Aspect
Ratio
|
Scan
Mode
|
Frame
Rate (fps)
|
 |
1080p
|
1080
|
1920
|
16:9
|
Progressive
|
24
|
|
1080p
|
1080
|
1920
|
16:9
|
Progressive
|
30
|
|
1080i
|
1080
|
1920
|
16:9
|
Interlaced
|
30
|
|
720p
|
720
|
1280
|
16:9
|
Progressive
|
24
|
|
720p
|
720
|
1280
|
16:9
|
Progressive
|
30
|
|
720p
|
720
|
1280
|
16:9
|
Progressive
|
60
|
 |
480p
|
480
|
704
|
16:9
|
Progressive
|
24
|
|
480p
|
480
|
704
|
16:9
|
Progressive
|
30
|
|
480p
|
480
|
704
|
16:9
|
Progressive
|
60
|
|
480p
|
480
|
704
|
4:3
|
Progressive
|
24
|
|
480p
|
480
|
704
|
4:3
|
Progressive
|
30
|
|
480p
|
480
|
704
|
4:3
|
Progressive
|
60
|
|
480p
|
480
|
640
|
4:3
|
Progressive
|
24
|
|
480p
|
480
|
640
|
4:3
|
Progressive
|
30
|
|
480p
|
480
|
640
|
4:3
|
Progressive
|
60
|
 |
480i
|
480
|
704
|
16:9
|
Interlaced
|
30
|
|
480i
|
480
|
704
|
4:3
|
Interlaced
|
30
|
|
480i
|
480
|
640
|
4:3
|
Interlaced
|
30
|
Vertical Scan Lines
Vertical scan lines refer to the number of horizontal lines a
television can display to create an image. As the number of lines
increase, more information is displayed, resulting in better picture
quality. Traditional analog TVs can display approximately 480
lines, while high-definition television can display up to 1080
lines.
Horizontal Pixels
Each horizontal line in a TV is made up of individual dots (pixels).
The higher the number of pixels, the finer the TV picture becomes.
Horizontal pixel measurements using today's technology can range
from 250 for a VCR to as much as 500 for a DVD player. Typical
digital TV broadcasts have at least 640 pixels.
Aspect Ratio
Aspect ratio identifies the ratio of the TV screen's width over
its height. A 16:9 aspect ratio refers to a wide-screen picture
format, while a 4:3 refers to a standard TV format.
Scan Mode
Interlaced scanning is a method that creates a TV picture with
alternating lines of information and is the cause for flickering.
Progressive scanning is a method that creates a TV picture with
consecutive lines of information that results in flicker-free
picture quality.
Frame Rate
Motion picture on your TV is generated by a series of still pictures
that changes from picture to picture at a very fast rate. This
rate is measured by the number of still pictures (frames) displayed
within one second of time. The higher the frame-rate, the smoother
the picture displayed.
- What
are the different display technologies used in Digital Televisions?
Digital televisions use the same display technologies available
today for analog TVs and computer monitors. They include CRT (Cathode
Ray Tubes), LCD (Liquid Crystal Displays), front and rear projection,
and PDP (Plasma Display Panels). Most digital TVs today use CRT
and projection technologies; however, the CRT maintains an advantage
over projection technologies with a wider viewing angle that makes
it more suitable for living room viewing.
- How
is a HDTV/EDTV/SDTV different from a HDTV/EDTV/SDTV Monitor?
In order to receive digital broadcasts, a digital decoder must
be used to receive and decode digital broadcast signals. Digital
decoders can be built into the digital television itself or they
may come in the form of a set-top box that is added separately
to the television. HDTV/EDTV/SDTV Monitors are digital televisions
without a digital decoder built into the television. HDTV/EDTV/SDTV
Monitors give you the flexibility to add a digital decoder in
the future when digital broadcasts are more prevalent.
- What
are the benefits of a Digital Television?
The primary benefits of digital televisions are superior picture
quality and better sound. The analog TV signals we watch today
are made of 525 interlaced lines and are subject to screen flickering,
ghost-shadows, and blurring. Digital televisions are dramatically
different in that they receive signals digitally in the form of
0s and 1s so problems with ghost-shadows and blurring go away.
Digital signals also produce a higher quality TV picture, displaying
crisp, sharp and vivid images using up to 1080 lines instead of
525 lines. Additionally, digital television signals can deliver
cinema-quality sound effects using 6-channel Dolby Digital surround
sound instead of only two regular stereo channels.
- Are digital
broadcasts available now?
Digital broadcasts are available through terrestrial (antenna),
satellite, and in the near future, cable systems. Major television
networks such as ABC, NBC, CBS, Fox, and HBO have already begun
broadcasting digital TV programming.
- Do I
need component inputs or RGB inputs for my DTV?
RGB inputs and component inputs are the
best connectivity interface for use with todays high-resolution
digital sources such as DVD players (standard or progressive)
and HDTV decoder set-top boxes. RGB and component inputs work
with video signals that are split into its base components, resulting
in a cleaner and purer video signal than all other connection
options. There are two types of component inputs and Sampo HDTV
Monitors/TVs are equipped with both. The standard component inputs
can accept 480i signals while the high-definition component inputs
can handle 480i, 480p, 720p, and 1080i signals from progressive
DVD players and HDTV decoder set-top boxes.
- Can
I connect a DTV to my PC or Laptop?
Yes, as long as the digital television is equipped with an RGB
input (15-pin D-sub connector). A digital television is essentially
a high quality computer monitor capable of displaying various
resolutions from today's advanced video cards. All Sampo HDTV
Monitors/TVs are equipped with an RGB-output that lets you connect
multiple monitors in series for multimedia presentation purposes.
- What
does "down-convert" mean?
Down-convert takes place when a digital broadcast signal exceeds
the display capabilities of the digital television and the broadcast
signal is reduced to match the television's limited display capabilities.
For example, if NBC broadcasts a digital program using 1080 lines
(1080i format) while the digital television is only able to display
480 lines (480i or 480p), the 1080i signal is reduced or down-converted
to only 480 lines, resulting in inferior picture quality. Sampo
HDTV Monitors/TVs can display all digital resolutions from 480
lines to high-definition 1080 lines, eliminating the need for
the HDTV decoder to down-convert broadcast signals.
- What
does "up-convert" mean?
Up-convert takes place when a digital television's display capabilities
exceed the digital broadcast signal and the broadcast signal is
increased to match the TV's display program using 480 lines (480i
or 480p) and the digital television is able to display 1080 lines,
the signal is increased or up-converted to match the TV, resulting
in hazy picture quality. Sampo HDTV Monitors/TVs can display all
digital resolutions from 480 lines to high-definition 1080 lines,
eliminating the need for the HDTV decoder to up-convert broadcast
signals.
- Are
digital televisions compatible with my existing video equipment?
Most digital televisions are compatible with your existing video
equipment; however, this depends on the types of connectivity
options available on the digital TV. All Sampo HDTV Monitors/TVs
are equipped with multiple connection options for connections
with your existing video equipment including VCRs, DVD players,
Progressive DVD players, LaserDisc/VideoCD Players, analog and
digital camcorders, Digital VHS players, and video game machines.
- What
will the future of digital television look like?
The broad bandwidth of the new digital television system facilitates
a whole new spectrum of programming and data services for your
home. For example, this bandwidth allows at least 4 standard-definition
TV broadcasts to simultaneously display on your digital TV screen,
in addition to displaying data content such as news, stock reports,
email, and other data related services. In the near future, your
digital television will become an information resource hosting
multiple broadcasts in multiple windows while displaying data
content in banner strips.
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