History of television Tom Suk 145 History of

History of television Tomáš Suk 1/45

History of television • Television - transmitting moving images • Joke from times of Soviet Union • Who invented television? 2/45

History of television • • Television - transmitting moving images Joke from times of Soviet Union Who invented television? Inventor of television was some Jefim Kolorovič Televizenko, who transmitted images from a gallery to his home. 3/45

History of television • Alexander Bain 1843 transmitted individual pictures – more fax than television 4/45

History of television • Johann Wilhelm Hittorf 1869 – cathode ray tube (CRT – katodová trubice) • Willoughby Smith 1873 – photoconductivity of selenium 5/45

Mechanical television • Paul Julius Gottlieb Nipkow – German technician (* 1860 Lauenburg (Lębork) – 1940 † Berlin) • Nipkow disk (Nipkowův kotouč) 1884 6/45

Mechanical television 7/45

Mechanical television While viewing mechanical television, one was literally glued to the set Felix the Cat as he looked in 60 -line pictures during a 1928 telecast by RCA-NBC 8/45

Mechanical television 9/45

Spinning disk confocal microscopy • It focuses the excitation laser through a series of many pinholes on a rapidly rotating disk to accelerate the scanning process. 10/45

Analog television • Georges Rignoux, A. Fournier, Paris 1909 – matrix of 8× 8 selenium cells • Kenjiro Takayanagi 1925 CRT displaying television signal – first receiver • Vladimir Kosmich Zworykin 1933 iconoscope – first electronic camera • November 2, 1936, BBC – first public regular TV broadcasting • May 1, 1953 – TV broadcasting in Czechoslovakia 11/45

Analog electronic camera • Iconoscope • Super-iconoscope • Separate photocathode and accumulative cathode to use secondary emission 12/45

Analog electronic camera • Orthicon • Super- orthicon 13/45

Analog electronic camera • Vidicon • Plumbicon Based on semiconductors: vidicon – one type, Plumbicon – PN junction 14/45

Black-and-white CRT (černobílá obrazovka) • Deflection coils (vychylovací cívky) • Phosphor (luminofor) - zinc cadmium sulfide and zinc sulfide silver, the Zn. S: Ag+(Zn, Cd)S: Ag 15/45

Black-and-white CRT 16/45

Standards • 30 frames/s, 525 lines per frame, line frequency 15 750 Hz, video bandwidth 5. 5 MHz • 25 frames/s, 625 lines per frame, line frequency 15 625 Hz, video bandwidth 6. 5 MHz Aspect ratio 4: 3 17/45

Interlacing (prokládané řádkování) Contrary to progressive scan (neprokládané řádkování) 18/45

Interlacing (prokládané řádkování) • Frame – two fields (half frames) • Snímek – dva půlsnímky 19/45

One-line signal ¬ Horizontal synchronization (sync separator) (řádkový synchronizační impuls) 20/45

Vertical synchronization (snímkový synchronizační impuls) 21/45

Amplitude modulation • Radio carrier wave – modulated amplitude 22/45

Amplitude modulation DK (OIRT) BG (CCIR) Audio is frequency-modulated 23/45

Color television • • • John Logie Baird 1928 – Nipkow disk, 3 spirals of apertures, color filters, 3 color light sources at the receiver, commutator 24/45

Color television • NTSC (National Television System Committee) • Luminance Y=0. 3 R+0. 59 G+0. 11 B • Chrominance I=0. 6 R-0. 28 G-0. 32 B (in-phase) Q=0. 21 R-0. 52 G+0. 31 B (quadrature) January 1, 1954 USA – first regular color broadcast 25/45

NTSC • Amplitude-phase (quadrature) modulation • 3. 579545 MHz color carrier • Two carriers, phase difference 90°, amplitude modulation of I and Q § phase = hue § amplitude = saturation 26/45

NTSC • Colorburst (synchronizační impuls barvy) • Detail of spectrum • color carrier fb America fb=227. 5 ∙ 15750 Hz=3579545 Hz Europe fb=283. 5 ∙ 15625 Hz=4429687. 5 Hz 27/45

NTSC • disturbing pattern from the chrominance signal on the black and white screen 28/45

PAL • Phase alternating line (fáze střídající se po řádcích) • Chrominance U=R-Y, V=B-Y • Even field: F=(U, V) • Odd field: F*=(U, -V) 29/45

SECAM • Séquentiel couleur à mémoire – postupný přenos barev s pamětí • Odd lines V, even lines U, the other signal from memory from the previous line • Frequency modulation 30/45

Color analog camera • Semi-transparent mirrors 31/45

Analog television receiver • Block diagram 32/45

Analog television receiver • Matrix circuit 33/45

Analog television receiver • Color CRT 34/45

Color CRT • Dot phosphor (delta gun) color CRT • Inline (or Trinitron) color CRT 35/45

Phosphor for color CRT Blue – zinc sulfide with few ppm of silver Green – zinc sulfide with copper Red – yttrium oxide-sulfide activated with europium 36/45

Present time • Camera – Charge-Coupled Device (CCD – nábojově vázaný prvek) • Digital Video Broadcasting (DVB – digitální televizní vysílání) • Screen – Liquid Crystal Display (LCD – Displej z tekutých krystalů) – Organic light-emitting diode (OLED – organické svítící diody) 37/45

Digital television • • DVB-T (Terrestrial) DVB-T 2 (Second generation terrestrial) DVB-S (Satellite) DVB-C (Cable) DVB-T 2 – in Prague from 1 st March 2017 DVB-T – last broadcast in 2021 38/45

Orthogonal frequency-division multiplexing modulation (OFDM) • A large number of closely spaced orthogonal subcarriers that are transmitted in parallel 39/45

Orthogonal frequency-division multiplexing modulation (OFDM) • Orthogonal frequencies – peaks of subcarriers line up with the nulls of the other subcarriers • Overlap of spectral energy – original signal can be recovered 40/45

Orthogonal frequency-division multiplexing modulation (OFDM) • Transmitter – inverse Fourier transformation • Receiver – Fourier transformation 41/45

Digital television • Standard codecs: o MPEG-4 AVC (H. 264) - DVB-T o MPEG-H HEVC (H. 265) - DVB-T 2 • A few digital channels in one original analog bandwidth – multiplex o DVB-T: 4 channels SD or 1 channel HD o DVB-T 2 : 16 channels SD or 4 channel HD 42/45

Difference between DVB-T and DVB-T 2 43/45

Digital television • Hybrid Broadcast Broadband Television (Hbb. TV) • Standard for connection of television and internet 44/45

History of television • Thank you for your attention 45/45