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Television
(An Insight)
Presented By: Hafiz Farhan

Types of TV
? There are two type of TV
? Analog Televisions
? Used in the old day
? Limited functionality
? Low cost
? Low resolutions
? Digital Televisions
? TV of modern era with diverse features
? Multitasking
? Similar cost
? High quality

Analog TV
? analog circuit components
? Signal were processed in analog form
? e.g.:
? Picture Tube
? Filters
? Antenna
? Controls

Digital TV
? It has several advance features and have better quality
? Signal are converted in to digital form (ADC)
? Digital circuit components are used
? RAM
? Processor
? Clock
? Remote Control
? LEDs

Protocols
? There are certain standards which are followed such as
? Video (MPEG, MP4, HDTV, etc.)
? Audio (MP3, etc.)
? Modulation
? Amplitude Modulation
? Frequency Modulation
? Phase Shift Modulation
? etc.
? Compression & Decompression
? Encoding & Decoding
? Others

6
Monochrome TV Signals (NTSC)
? In the NTSC monochrome system the luminance signal is AM/VSB
(Amplitude Modulation/Vestigial Sideband) modulated onto the video
carrier
? The sound signal is FM modulated onto the Audio Sub-Carrier located 4.5
MHz from the video carrier
0 4.5 MHz
Video
Signal
Audio
Signal
Video
Carrier
Audio
Sub-Carrier

Signal Receiving
? First step is to receive the signals
? There are various methods to receive the signals
? Wireless
? Antenna
? Dish Antenna
? Wifi e.g. Wi-Tribe
? Wired
? Cable
? Internet (IP) e.g. PTCL Smart TV

Modulation of
Analog Signal
(AM & FM)

Modulation of
Digital Signal
(AM & FM)

Note
? So we can see that both Signals are received in analog form

Components of a
television system
(Analog)

Components of a
television system
(Analog)
These are the
image intensities
at different
regions

Components of a
television system
(Analog)
These signals act
as coordinates
signal for the
image

Analog TV (CRT / Picture Tube)
Design of circuits, protocols
and formats may vary
country wise

Thus, a ��composite video signal�� contains:
1. Intensity information
2. Horizontal retrace
3. Vertical retrace

Digital TV (LEDs, LCDs)
Basic Block Diagram of Digital TV

Comparisons
? Digital TVs can store data where as analog cannot do so
? Digital TV consume less power than the other
? Digital TV Provide High Quality
? Heavy signal processing is required in digital TVs as compared to
analog TVs

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