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TELEVISIONTELEVISION
“to see at a distance”
TELEVISION BROADCASTINGTELEVISION BROADCASTING
The science of transmitting rapidly changing pictures from one point to another by means
of electrical signals.
DEFINITIONS
1. STUDIO OR OUTSIDE THE
STATION
2. PICTURE AND SOUND TRANSMITTER
COMPONENTS OF A COMPLETE TV BROADCASTING SYSTEM
COMPONENTS OF A COMPLETE TV BROADCASTING SYSTEM
3. MEDIUM (COAXIAL CABLE / FIBER OPTIC CABLE
4. A NUMBER OF RECEIVERS
STL – STUDIO TO TRANSMITTER LINK
ENG – ELECTRONIC NEWS GATHERING
ACRONYMS
SNG – SATELLITE NEWS GATHERING
SEG – SPECIAL EFFECTS
GENERATOR
EFP – ELECTRONIC FIELD PRODUCTION
ACRONYMS
DIPLEXERDIPLEXERA special coupling device that permits the transmission of both audio and video signals using one antenna system.
VSB – VESTIGIAL VSB – VESTIGIAL SIDEBANDSIDEBANDTo conserve
electromagnetic spectrum, it produces
only the full USB and only a portion of the LSB
DEFINITIONS
MONOCHROMEMONOCHROMEShades of black, gray and
whiteCOLORCOLOR
Red, green and blue
TV BROADCAST TV BROADCAST CHANNELCHANNEL
The band of frequencies assigned for the transmission of the picture and sound signals.
TV BROADCASTING FREQUENCY ALLOCATION
CHANNEL CHANNEL NUMBERNUMBER
FREQUENCY FREQUENCY RANGE RANGE (MHz)(MHz)
1 44 - 5054 - 6060 - 6666 - 7276 - 82
6 82 - 88
43
5
2
174 - 180180 - 186186 - 192192 - 198198 - 204204 - 210210 - 216
7
12
109
11
8
13
ANALOG COLOR TV SYSTEMS IN THE WORLD (ASPECT RATIO, 4:3)
UPPER VHF – CHANNELS 7 - 13
UHF – CHANNELS 14 - 83
FLOWER = 6N + 132
FLOWER = 6N + 386
470 – 890 MHz
TV BROADCASTING STANDARDS
PARAMETERSPARAMETERS RP STANDARDRP STANDARD
Broadcasting Band
54 – 890 MHzCh 2 to 4 (54 – 72 MHz) VHF Low
Ch 5 to 6 (76 – 88 MHz)Ch 7 to 13 (174 – 216 MHz) VHF
HighCh 14 to 83 (470 – 890 MHz) UHFChannel width 6 MHzBaseband Freq Video: 0 – 4 MHz Audio: 50 Hz – 15
kHz
PARAMETERSPARAMETERS
Max no. of stations
25 stationsPicture IF: 45.75 MHzSound IF: 41.25 MHz
Picture Carrier: +/- 1000 HzColor Carrier: +/- 10 Hz
Sound Carrier: +/- 1000 Hz
Fc Tolerance
IF - Rx
CircularPolarization
TV BROADCASTING STANDARDS
RP STANDARDRP STANDARD
PARAMETERSPARAMETERS
Type of Emission Video: C3EAudio: F3E (mono)
Multi-channel TV Sound (stereo)Audio : FM
Video: AM / Vestigial SidebandReceiver SuperheterodyneType of
PropagationSpace wave
Modulation
TV BROADCASTING STANDARDS
RP STANDARDRP STANDARD
STANDARDS FOR ANALOG TV SYSTEM
PARAMETERSPARAMETERS American , NTSCAmerican , NTSC
No. of lines/frame 525No. of lines/field 262 ½ (odd/even)
No. of frames/sec 30Field frequency 60 (59.94) HzLine frequency 15,750 (15,735.36)
HzChannel width 6 MHzVideo bandwidth 4 MHz
European, PALEuropean, PAL
625312 ½ (odd/even)
2550 Hz
15,625 Hz7 MHz5 MHz
PARAMETERSPARAMETERS American, NTSCAmerican, NTSC
Color Subcarrier 3.58 MHzSound System FM
Max Sound Deviation
+ / - 25 kHzIntercarrier Frequency
4.5 MHz
European, PALEuropean, PAL
4.43 MHzFM
+ /- 50 kHz5.5 MHz
STANDARDS FOR ANALOG TV SYSTEM
SCANNINGSCANNING
The process of analyzing successively
according to a pre-determined method, the
light values of picture elements constituting the total picture area
INTERLACED INTERLACED SCANNING PATTERNSCANNING PATTERN
Odd fields first then even fields; from left to right; then from top to
bottom
SCANNING
HORIZONTAL SCANNING FREQUENCY : 15,750 HzVERTICAL SCANNING FREQUENCY : 60 Hz
Progressive scan differs from interlaced scan in that the image is displayed on a screen by scanning each line (or
row of pixels) in a sequential order rather than an alternate order, as is done with interlaced scan.
PROGRESSIVE SCANNING PATTERNPROGRESSIVE SCANNING PATTERN
SCANNING
SYNCHRONIZATIONSYNCHRONIZATION
Keeps the transmitter and receiver scanning in step with each other
Rectangular pulses
SYNCHRONIZATION
HORIZONTAL SYNC FREQUENCY : 15,750 HzVERTICAL SYNC FREQUENCY : 60 Hz
Occur during blanking time when no picture information is sent (blacker than
black region)
EQUALIZATIONEQUALIZATION
Serves to maintain continuous flow of sync information to the horizontal
scanning system.
EQUALIZATION
EQUALIZING PULSE FREQUENCY : 31,500 Hz
Occur before and after each V sync pulse
BLANKINGBLANKING
Prevents the electron beam from reaching the screen, thus
retraces (flyback) are made invisible.
BLANKING
HORIZONTAL BLANKING FREQUENCY : 15,750 Hz
VERTICAL BLANKING FREQUENCY : 60 Hz
NEGATIVE TRANSMISSIONNEGATIVE TRANSMISSION
As the signal increases, the picture
becomes darkerCOMPONENTS OF A COMPONENTS OF A COMPOSITE VIDEO COMPOSITE VIDEO
SIGNALSIGNAL
Picture (video)
DEFINITIONS
Lowest amplitudes are the whitest color
Blanking pulses
Sync (H and V)
a. a. BRIGHTNESSBRIGHTNESSOverall or average intensity of illumination
which determines the background level in the reproduced picture
b. CONTRASTb. CONTRASTDifference in intensity between black and
white parts of the reproduced picture
PICTURE QUALITIES
c. DETAILc. DETAILDepends on the number of
picture elements that can be produced within the frame.
d. COLOR d. COLOR LEVELLEVELThe color should vary the picture
from no color to pale and medium colors up to vivid
intense color.
Also known as Resolution or Definition
PICTURE QUALITIES
e. HUEe. HUEThe color of the
object
f. ASPECT f. ASPECT RATIORATIOThe ratio of the width to
the height of the picture frame.
g. VIEWING g. VIEWING DISTANCEDISTANCE
Standard: 4:3
4 to 8 times the picture height
SPECIAL FACILITIES IN CAMERA ASSEMBLY
5. IRIS 5. IRIS CONTROLCONTROLLevel of illumination
6. MECHANICAL 6. MECHANICAL FOCUSFOCUSCw / ccw or lock to a
scene7. 7.
VIEWFINDERVIEWFINDERTo find a sample of the material
SPECIAL FACILITIES IN CAMERA ASSEMBLY
1. 1. INTERCOMMUNICATIONINTERCOMMUNICATION
2. MULTIPLE LENS 2. MULTIPLE LENS TURRETTURRETCollection of different
lenses3. TALLY 3. TALLY LIGHTSLIGHTSMounted on camera
housing ; “on air”
4. PAN / TILT 4. PAN / TILT CONTROLSCONTROLSUp/down; left/right; zoon
in/out
1. 1. PHOTOEMISSIONPHOTOEMISSIONLiberation of electrons
from a material under the influence of
illumination
2. 2. PHOTOCONDUCTIONPHOTOCONDUCTION
Changes of conductivity of a surface due to
illumination
METHODS OF PRODUCING AN IMAGE WITHIN THE TUBE
3. PHOTOVOLTAIC 3. PHOTOVOLTAIC ACTIONACTIONGeneration of voltage due
to chemical or physical changes induced by
illumination
1. LIGHT 1. LIGHT TRANSFER TRANSFER CAPABILITYCAPABILITY
Ratio of brightness variations in the
reproduced image to the brightness variations in
the original scene
2. SPECTRAL 2. SPECTRAL RESPONSERESPONSESame as the eye; colors
are rendered in their proper tones
CHARACTERISTICS OF CAMERA TUBES
3. SENSITIVITY3. SENSITIVITYUnit: Lumen; output
photosignal per incident illumination
4. DARK 4. DARK CURRENTCURRENT
Small amount of signal current flowing in the output circuit even in
the absence of illumination on the
faceplate of the tube.
5. LAG 5. LAG CHARACTERISTICCHARACTERISTIC
Inability of the photosensitive layer in the
pick up tube to follow faster changes in illumination.6. RESOLVING 6. RESOLVING
POWERPOWERResolution
power
CHARACTERISTICS OF CAMERA TUBES
The light image is transformed into an electronic image, which can then be read from the back of
the target by a beam of electrons.
HOW CAMERA TUBES WORK
In a camera tube pickup device, the front of the tube contains a layer of photosensitive material
called a target. The lens of a camera focuses light from a scene onto the front of the camera tube, and this light causes
changes in the target material.
This varying voltage is the electronic television signal.
HOW CAMERA TUBES WORK
The beam of electrons is produced by an electron gun at the back of the camera tube.
The beam is controlled by a system of electromagnets that make the beam
systematically scan the target material.
Whenever the electron beam hits the bright parts of the electronic image on the target
material, the tube emits a high voltage, and when the beam hits a dark part of the image,
the tube emits a low voltage.
TYPES OF CAMERA TUBES
1. NIPKOW DISK1. NIPKOW DISK
A photoelectric tube is used with a rotating wheel punched with
small holes spiraling in toward the center to
scan the picture elements.
2. IMAGE 2. IMAGE DISSECTOR / DISSECTOR / ICONOSCOPEICONOSCOPEThe first all electric pick
up device.
3. IMAGE 3. IMAGE ORTHICONORTHICONIndicates the linear
relation between light input and signal output;
highly sensitive but relatively large and
expensive.
TYPES OF CAMERA TUBES
4. FLYING SPOT 4. FLYING SPOT SCANNERSCANNERThe spot of light from the screen
of the CRT is used as the light source to scan a film slide
5. VIDICON5. VIDICONMost widely used; a very small
camera tube of relatively simple construction, a photoconductive target plate and an electron gun.
Image plate is made up of Antimony Trisulfide
TYPES OF CAMERA TUBES
6. PLUMBICON (PHILIPS)6. PLUMBICON (PHILIPS)Similar to the Vidicon except that the image plate is made of Lead
Oxide (PbO)7. SATICON (HITACHI, 7. SATICON (HITACHI,
LTD)LTD) The image plate is made of Selenium, Arsenic and Tellurium.
8. SILICON VIDICON8. SILICON VIDICONA Silicon semiconductor junction is used for the target
material; extremely high sensitivity for low light applications.
TYPES OF CAMERA TUBES
9. CHALNICON 9. CHALNICON (TOSHIBA)(TOSHIBA)
The target is a multilayer arrangement consisting of Tin Oxide, Cadnium Selenide and Arsenic Trisulfide; very high
sensitivity.
10. NEWVICON (MATSUSHITA 10. NEWVICON (MATSUSHITA ELECTRIC)ELECTRIC)
The target is made of Amorphous Zinc Selendie layer backed by Antimony Trisulfide.
TYPES OF CAMERA TUBES
CHARGE COUPLED DEVICE
A charge-coupled device (CCD) is a light-sensitive integrated circuit that stores and displays the data for an image in such a way that each pixel (picture
element) in the image is converted into an electrical charge the intensity of which is related to a color in
the color spectrum
CHARGE COUPLED DEVICE
In a CCD, the light from a scene strikes an array of photodiodes
arranged on a silicon chip.
Photodiodes are devices that conduct electricity when they are struck by light; they send
this electricity to tiny capacitors.
The capacitors store the electrical charge, with the amount of charge stored
depending on the strength of the light that struck the photodiode.
The CCD converts the incoming light from the scene into an
electrical signal by releasing the charges from the photodiodes in
an order that follows the scanning pattern that the
receiver will follow in re-creating the image.
CHARGE COUPLED DEVICE
CRITERIA FOR COMPATIBILITYCRITERIA FOR COMPATIBILITY
1. The color TV system must transmit and be capable of receiving a luminance signal
which is either identical to a monochrome transmission or easily converted to it.
2. Must use the same 6 MHz bandwidth
3. Must transmit the Chrominance information in such a way that it is sufficient for adequate color reproduction but easy to
ignore by a monochrome receiver.
COLOR TV SYSTEM
1. LUMINANCE1. LUMINANCEIndicates the amount of light intensity, which is perceived
by the eye as brightness.Contains all information
required to construct a black and white picture from the
signal
Where: R – Red video signal
G – Green video signalB – Blue video signal
PRIMARY COLOR SIGNALS
Y = 0.30R + 0.59G + Y = 0.30R + 0.59G + 0.11B0.11B
2. 2. CHROMINANCECHROMINANCE
Term used to combine both hue (amplitude of C
signal) and saturation (phase angle)
Is the 3.58 MHz color subcarrier with
quadrature modulation by I and Q color signals
a. IN-PHASE CHROMINANCEa. IN-PHASE CHROMINANCEColor video signal transmitted as amplitude
modulation of the 3.58 MHz C signalThe only color video signal with bandwidth
of 0 to 1.3 MHz
I = 0.60R – 0.28G – I = 0.60R – 0.28G – 0.32B0.32B
The positive polarity of the I signal is orange while the negative polarity is cyan
CHROMINANCE SIGNALS
b. QUADRATURE PHASE CHROMINANCEb. QUADRATURE PHASE CHROMINANCE
Color video signal that modulates the 3.58 MHz C signal in quadrature with the I signal
with bandwidth of 0 to 0.5 MHz
Q = 0.21R – 0.52G + Q = 0.21R – 0.52G + 0.31B0.31B
The positive polarity of the Q signal is purple while the negative polarity is yellow green
CHROMINANCE SIGNALS
ANALOG COLOR TV SYSTEMS IN THE WORLD (ASPECT RATIO, 4:3)
NTSC
National Television Standards Committe
e (American
)
Phase Alteration
by Line (British, German)
PAL
Sequential Color and Memory (French)
SECAM
SIMILARITYSIMILARITYThey separate the luminance and chrominance information and
transmit the chrominance information in the form of 2 color difference signals which modulate a color subcarrier frequency
transmitted within the sideband of the luminance signal.
DIFFERENCEDIFFERENCE
COLOR TRANSMISSION STANDARDS
The processing of the chrominance informationNTSC – subcarrier frequency is amplitude modulated
PAL – subcarrier frequency is phase modulatedSECAM – subcarrier frequency is frequency modulated
COLOR COMBINATIONS
GREEN + RED =
GREEN + BLUE =
BLUE + RED =
GREEN + BLUE + RED =
YELLOW
MAGENTA
CYAN
WHITE
Retransmit the signals of TV broadcast station by
frequency conversion and amplification without
significantly altering any characteristic except the amplitude and frequency.
1. TRANSLATORS1. TRANSLATORS
OTHER TV SERVICES
2. CATV – CABLE TELEVISION2. CATV – CABLE TELEVISION
A communications system that gathers local , remote, playbacks and satellite
signals and sent by coaxial cables to the subscribers.
OTHER TV SERVICES
A. A. HEADENDHEADENDThe main hub of the CATV system where the signals from all
sources originate, then processed, amplified and distributed to the subscribers.
PARTS OF THE CATV SYSTEM
B. OUTSIDE PLANTB. OUTSIDE PLANTPart of the CATV system that provides the distribution of the
TV signals from the head end to the paying subscribers.
C. SUBSCRIBER PREMISE EQUIPMENTC. SUBSCRIBER PREMISE EQUIPMENTThe end of the line of the CATV system, where the cable signals were delivered from its origin to the subscriber.
3. MATV – MASTER ANTENNA TELEVISION3. MATV – MASTER ANTENNA TELEVISION
The means by which many apartments, houses, hotels, schools and other multi-unit buildings distribute TV and FM signals to a
number of receivers.
OTHER TV SERVICES
DIVISIONSDIVISIONS
1. Head end
2. Distribution System
A. A. HEADENDHEADENDNormally consists of an antenna installation to receive the
desired signals, processing equipment to filter the signals and remove interference, and a distribution amplifier to amplify the signals to the level required to provide an adequate signal to
every receiver in the system.
PARTS OF THE MATV SYSTEM
B. DISTRIBUTION SYSTEMB. DISTRIBUTION SYSTEM
Provides a clean signal to the sets by isolating each receiver from the system and by delivering the proper amount of
signal to each set
4. CCTV – CLOSED CIRCUIT TELEVISION4. CCTV – CLOSED CIRCUIT TELEVISION
A TV system that operates on a closed loop basis; CCTV images
are only available to those connected to the closed loop.
OTHER TV SERVICES
Applications: educational, business, industry, medicine, traffic control, surveillance
Components: Camera and lens, Coaxial cables, Monitors, Video
Cassette/Tape Recorders
This process produces much clearer picture and sound
quality than analog systems, similar to the difference between a compact disc recording (using digital
technology) and an audiotape or long-playing record.
DIGITAL TELEVISION
A device that receives, decodes, and displays
digital video broadcasts (in both high-definition and standard-definition formats) for consumer
viewing.
Digital television uses technology that records, transmits, and decodes a signal in digital form—that is, as a series of ones and
zeros.
It also permits additional features to be embedded
in signals including program and consumer information as well as
interactivities.
There are three types of broadcast digital television (DTV), each with progressively better
picture and sound quality:
TYPES OF DIGITAL TELEVISION
Digital technology is being developed
that will offer sharper pictures on wider screens, and HDTV with cinema-
quality images. High-Definition TV (HDTV)
Standard-Definition TV (SDTV)
Enhanced-Definition TV (EDTV)
480i 480 lines by 720 pixels
wide, displayed in interlaced format.
Committee established by the FCC to define new standards for publicly regulated broadcast television in
the United States
Advanced Television Systems Committee (ATSC)
STANDARD DEFINITION TELEVISION
It has a 4:3 or 16:9 aspect ratio, 29.97-Hz frame rate, as defined
by the ATSC standard.
High-definition television (HDTV) image that is 480
vertical lines by 720 horizontal pixels displayed in progressive
format
480p
ENHANCED DEFINITION TELEVISION
It has a 4:3 or 16:9 aspect ratio, 59.94 Hz, 29.97 Hz, and
23.98 Hz frame rates, as defined by the ATSC standard
HIGH DEFINITION TELEVISION
High-definition video formats that have 16:9 aspect ratio. Generally refers to 1080i or 720p images.
1,080 vertical lines by 1,920
horizontal pixels wide, displayed in
an interlaced format.
It has a 16:9 aspect ratio, 29.97
Hz frame rate,
1080i 720 vertical lines
by 1,280 horizontal pixels wide, displayed in
progressive format.
It has a 16:9 aspect ratio, 59.94 Hz, 29.97 Hz, and
23.98 Hz frame rates,
720p
Many flat panel TVs use liquid-crystal display (LCD) screens that make use of a special substance that changes properties when a
small electric current is applied to it.
LCD technology has already been used extensively in laptop
computers. LCD television screens are flat, use very little electricity, and work well for small, portable television sets.
FLAT PANEL TELEVISION
Flat panel TVs made from gas-plasma displays can be much
larger. In gas-plasma displays, a small electric current stimulates an inert gas sandwiched between
glass panels, including one coated with phosphors that emit
light in various colors. While just 8 cm (3 in) thick,
plasma screens can be more than 150 cm (60 in) diagonally.
FLAT PANEL TELEVISION