US2248549A - Television transmitter - Google Patents

Television transmitter Download PDF

Info

Publication number
US2248549A
US2248549A US161775A US16177537A US2248549A US 2248549 A US2248549 A US 2248549A US 161775 A US161775 A US 161775A US 16177537 A US16177537 A US 16177537A US 2248549 A US2248549 A US 2248549A
Authority
US
United States
Prior art keywords
control electrode
impulses
resistance
frame
line
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US161775A
Other languages
English (en)
Inventor
Kurt Schlesinger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LOEWE RADIO Inc
Original Assignee
LOEWE RADIO Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by LOEWE RADIO Inc filed Critical LOEWE RADIO Inc
Application granted granted Critical
Publication of US2248549A publication Critical patent/US2248549A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/04—Synchronising
    • H04N5/06—Generation of synchronising signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/04—Synchronising
    • H04N5/06—Generation of synchronising signals
    • H04N5/067—Arrangements or circuits at the transmitter end
    • H04N5/0675—Arrangements or circuits at the transmitter end for mixing the synchronising signals with the picture signal or mutually
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/04—Synchronising
    • H04N5/06—Generation of synchronising signals
    • H04N5/067—Arrangements or circuits at the transmitter end
    • H04N5/073—Arrangements or circuits at the transmitter end for mutually locking plural sources of synchronising signals, e.g. studios or relay stations

Definitions

  • the present invention relates to television transmitters and particularly to such transmitters operating according to the interlaced line method and with an odd' number of lines per image.
  • the invention consists in a connection for transmitting the short line and the longer frame synchronising impulses.
  • a transmitter of the above character sends the frame synchronising impulses alternately at one end and in the middle of the last line of each picture field. If the impulses are taken from separate generators (output tubes of the synchronising impulses amplifiers) it is necessary to conduct them for modulating the transmitter onto a common lead, i. e. to mix them. The simplest way would be to switch both impulses in parallel via resistances. There arise, however, some difliculties which are overcome by the connection according to the invention.
  • Fig. 1 is a time diagram of the synchronising impulses when mixed by simple addition
  • Fig. 2 is a connection for mixing the impulses according to the invention
  • Figs. 3a and 3b are time diagrams of impulses mixed according to the invention, whilst Fig. 4 is a modification of Fig. 2.
  • the impulses of both kinds produced by separate generators are mixed in a special tube so that the arising amplitude is not higher than that caused by the single impulses.
  • Fig. 2 shows a diagram of the connection.
  • the frame change generator I passes its impulses to the lead 2.
  • the line change generator 3 is connected to supply its output to the lead 4.
  • the mixing tube 8 has two control electrodes or grids 9 and III. This tube 8 may further be provided with a screening grid I I and an intercepting grid I2. A normal four or five electrode valve may be used which by way of an anode resistance I3 is connected to a suitable source of anode voltage, such as battery I4.
  • the leads 2 and 4 are connected by way of resistances 9a and We to the control grids 9 and I0 which are, in turn, earthed or grounded via resistances 9b, I0b. There accordingly flows a constant feed current, the intensity of which may be adjusted by the screening grid battery I la. This current is completely interrupted by the negative synchronisation impulses arriving at one of the grids 9 and I0. In this way there result in the output lead 20 positive impulses equal to the voltage drop at the anode resistance I3, and independent of whether lead 2 or 4 or both at once are excited. There is then obtained a synchronisation impulse diagram according to Fig. 3.
  • the desired phase advance is readily obtained by a resistancecapacity coupling.
  • Fig. 4 which is based on Fig. 2, a coupling of the above-described character is indicated by the resistance and capacity combination I9 and 20. If it is assumed that the duration of a frame change impulse is of the order of 10 seconds, the condenser may have 0.01 mi. capacity and the resistance 20 may be of the order of 10,000 ohms.
  • the advanced impulse so obtained is then supplied to the grid or control electrode 9 by way of the resistance 2
  • a reversing stage has to be provided.
  • the simplest way is to use a tube I l coupled by way of a condenser I5 to the mixing tube 8.
  • the control electrode or grid of tube I4 is earthed via resistances I1 and I6 and a bias battery I8, the latter having a voltage sufiicient to suppress the anode current in the position of rest.
  • the time constant of capacity I5 and resistor I6 has to be dimensioned so as to transmit satisfactorily an oscillation of a period equal to 10 times the duration of a frame synchronising impulse.
  • Resistance I'I causes the impulses tohave a rectangular form and a constant amplitude.
  • a synchronizing impulse mixing circuit comprising a frame synchronizing impulse generator, a line synchronizing impulse generator, a thermionic tube having at least a cathode, a first control electrode, a second control electrode and an anode, impedance coupling means directly connecting said frame synchronizing generator to said first control electrode, impedance coupling means directly connecting said line synchronizing impulse generator to said second control electrode, a first resistance connected between said first control electrode and said cathode, a second resistance connected between said second control electrode and said cathode, a serially connected resistor and source of potential connected between said anode and said cathode, and means to derive output energy from across said serially connected resistance.
  • a synchronizing impulse mixing circuit comprising a frame synchronizing impulse generator, a line synchronizing impulse generator, a thermionic tube having at least a cathode, a first control electrode, a second control electrode and an anode, impedance coupling means directly connecting said frame synchronizing generator to said first control electrode, impedance coupling means directly connecting said line synchronizing impulse generator to said second control electrode, a first resistance connected between said first control electrode and said cathode, a second resistance connected between said second control electrode and said cathode, a first current limiting resistance inserted between said first resistance and said first control electrode, and a second current limiting resistance inserted between said second resistance and said second control electrode.
  • a synchronizing impulse mixing circuit comprising a frame synchronizing impulse generator, a line synchronizing impulse generator, a thermionic tube having at least a cathode, a first control eldectrode, a second control electrode and an anode, impedance coupling means connecting said frame synchronizing generator to said first control electrode, impedance coupling means to connect said line synchronizing generator to said second control electrode, a series circuit comprising a capacity and resistance element having the capacity element connected intermediate the output of the frame synchronizing impulse generator and its associated impedance coupling means and the resistance connected to the cathode of the said thermionic tube, and a resistance element having one terminal connected intermediate the capacity and resistance of the said series circuit and the other terminal connected intermediate the line synchronizing impulse generator impedance coupling and the second control electrode of said thermionic tube, a first resistance connected between said first control electrode and said cathode, a second resistance connected between said second control electrode and said cathode,

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Endoscopes (AREA)
  • Cell Electrode Carriers And Collectors (AREA)
  • Noise Elimination (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Details Of Television Scanning (AREA)
US161775A 1936-09-05 1937-08-31 Television transmitter Expired - Lifetime US2248549A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE487560X 1936-09-05
DEL7408D DE1033257B (de) 1936-09-05 1936-10-26 Verfahren zur Mischung von Bildwechsel- und Zeilenimpulsen beim Fernsehen

Publications (1)

Publication Number Publication Date
US2248549A true US2248549A (en) 1941-07-08

Family

ID=41349324

Family Applications (2)

Application Number Title Priority Date Filing Date
US161775A Expired - Lifetime US2248549A (en) 1936-09-05 1937-08-31 Television transmitter
US167347A Expired - Lifetime US2227023A (en) 1936-09-05 1937-10-05 Interlaced line method

Family Applications After (1)

Application Number Title Priority Date Filing Date
US167347A Expired - Lifetime US2227023A (en) 1936-09-05 1937-10-05 Interlaced line method

Country Status (7)

Country Link
US (2) US2248549A (de)
BE (1) BE423429A (de)
CH (2) CH199610A (de)
DE (1) DE1033257B (de)
FR (2) FR826231A (de)
GB (2) GB487560A (de)
NL (1) NL58560C (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2485665A (en) * 1943-07-16 1949-10-25 Sperry Corp Mixing circuit
US2561817A (en) * 1950-02-02 1951-07-24 Avco Mfg Corp Automatic frequency control circuit
US2572849A (en) * 1945-01-04 1951-10-30 Oliver T Francis Vacuum tube impulse pattern producer
US2614247A (en) * 1947-12-26 1952-10-14 Fr Sadir Carpentier Soc Pulse modulating system
US2883659A (en) * 1942-03-18 1959-04-21 Sylvania Electric Prod Timing and phase-control circuits

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2416424A (en) * 1939-03-16 1947-02-25 Hazeltine Research Inc Synchronizing-signal separator
US2508923A (en) * 1946-06-27 1950-05-23 Rca Corp Synchronizing system
FR1407806A (fr) * 1964-06-25 1965-08-06 Thomson Houston Comp Francaise Perfectionnements apportés aux caméras de télévision

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2883659A (en) * 1942-03-18 1959-04-21 Sylvania Electric Prod Timing and phase-control circuits
US2485665A (en) * 1943-07-16 1949-10-25 Sperry Corp Mixing circuit
US2572849A (en) * 1945-01-04 1951-10-30 Oliver T Francis Vacuum tube impulse pattern producer
US2614247A (en) * 1947-12-26 1952-10-14 Fr Sadir Carpentier Soc Pulse modulating system
US2561817A (en) * 1950-02-02 1951-07-24 Avco Mfg Corp Automatic frequency control circuit

Also Published As

Publication number Publication date
CH219593A (de) 1942-02-15
BE423429A (de) 1937-10-30
GB487560A (en) 1938-06-22
FR828271A (fr) 1938-05-13
US2227023A (en) 1940-12-31
DE1033257B (de) 1958-07-03
NL58560C (de) 1946-12-16
GB504460A (en) 1939-04-25
FR826231A (fr) 1938-03-25
CH199610A (de) 1939-08-31

Similar Documents

Publication Publication Date Title
US2211942A (en) Circuit arrangement for separating electrical signal pulses
GB470495A (en) Improvements in or relating to multiplex signalling systems
US2248549A (en) Television transmitter
US2706265A (en) Multi-commutated channel amplifier
GB449242A (en) Improvements in apparatus for amplifying electrical variations
GB698296A (en) Improvements in or relating to television receiver circuit arrangements
GB648326A (en) Improvements in circuit arrangements for establishing the direct current level in television systems
US2265780A (en) Television receiving arrangement
US2281934A (en) Electrical impulse segregation circuits
US2105870A (en) Television apparatus
US2085402A (en) Method of and apparatus for producing electrical waves
US2363809A (en) Electronic tube circuit
US2425063A (en) Telegraphic keying bias adjuster
US2183966A (en) Periodic wave-generating system
US3178593A (en) Deflection waveform generator and amplifier
US2602896A (en) Saw-tooth wave generator
US2261762A (en) Interlaced scanning system
GB401634A (en) Improvements relating to electrical circuits for producing oscillations of non-sinusoidal wave form for use, for example, with cathode ray devices
US2221069A (en) Saw tooth wave generator
US2196825A (en) Oscillator
US2297612A (en) Television and like system
US2074496A (en) Television deflecting circuits
US2568541A (en) Television signal mixing circuit
US2315073A (en) Electric circuits
US2178736A (en) Television apparatus