Aug. 26, 1958 F. T. THOMPSON 2,849,648 TELEVISION APPARATUS Filed June 22, 1956

ON @C 2,849,648? Patented Aug. 26, 1958 ‘2 pulses applied to it to synchronize the yoscillator with the horizontal sweep circuit. However, it is understood 2,849,648 that the invention may be Ípracticed without the use of the damper to control the oscillator. TELEVISION APPARATUS It is, therefore, an object 4of the present invention T. Thompson, Pittsburgh, Pa., `assigner to West to provide an improved wobble deflection system for use llnghouse Electric Corporation, East Pittsburgh, Pa., with a television picture tube. a Vcorporation vof Pennsylvania A further object of this invention is to provide a Application June 22, 1956, Serial No. 593,201 wobble deflection system having a high Q which minimizes the driving power and reduces oscillator harmonics. 7 Claims. (Cl. 315-24) A further object of this invention is to provide a wobble deflection system wherein a desired high frequency de tìection wave can be easily obtained. A further object of the invention is to provide a wobble . Thisinvention relates to television receivers and the hke and, more particularly, to a spot wobble deflection deflection system whose phase is maintained the same at -the beginning of each lhorizontal line of the reproduced ’system for use with cathode ray tubes. The invention picture. has ­particular application to television picture ’tubes for j‘tïhe rreduction and elimination of the appearance of the A still further object of this invention is to provide a `individual horizontal lines which make up the image re 20 wobble deflection system 4having an output in synchronism produced on the screen of the picture tube. with the horizontal deñection circuit of a television 4re The trend toward the use of larger television picture ceiver. ` tubes lhas declined because of the practical limitations on These and other objects are effected by my invention viewing distance. The average room in a home in which as will be apparent from îthe following description taken a television receiver is located is too small to allow 25 in accordance with the accompanying drawings, through "comfortable viewing of a large screen television receiver. out which like reference characters indicate like parts, Alminimum viewing distance is imposed by the linestruc and in which: ¿ture fof lthe picture that is reproduced. The scanning Figure l is a block diagram of a television receiver ’lines îbecome noticeable >when the receiver is viewed more system in ’which the invention is applicable; and Iclosely vand ­the illusion of a continuous picture 'is lost. 30 Fig. 2 is a schematic diagram of a wobble deflection ‘It fis~especially desirable to eliminate the line structure system used in conjunction with 'the invention. ill-large screen television receivers to allow ‘these receivers In referring to Fig. l, there is illustrated a television lto'be comfortably viewed from a closer distance. receiver wherein incoming composite television signals, ­ ` v'It has been found that the line structure may ’be re including carrier modulated video and audio signals, vare "duced oryeliminated by adding a high frequency vertical 35 intercepted by an antenna 10 and applied to radio fre ~undu‘lation to a conventional scan, that is, >the cathode ray quency amplifier 11 wherein signals of predetermined ‘beam ¿is wobbled or oscillated vertically while itis hori- ` frequencies are selected and amplified. The desired sig fzontally scanning a raster on the screen of 'the picture nals are converted into carrier waves of intermediate tube. ‘In this case each horizontal ‘line of the picture frequency by converter 12 which heterodynes the lin ¿is kwidened and a flat or white field vis obtained. The 40 coming waves with waves ,produced by local oscillator high frequency vertical deñection effectively enlarges the 13. The ~intermediate frequency waves are applied to in vertical dimension of the electron beam spot without in termediate amplifier .14 wherein the signals are further creasing 'the horizontal dimension. selectedand amplified. Video signals are derived from AIn prior wobble deflection systems, circuits for oscillat the video modulated carrier wave by second detector 15 ing the electron beam of the picture 'tube utilized auxiliary which also functions to heterodyne the intermediate fre -deñection yokes or coils which are placed around 'the quency video ‘modulated carrier and the intermediate l'neck ­of the picture tube and which form part of the frequency audio carrier wave to provide 'an audio modu 4"resonant tank of the oscillatory circuit. An auxiliary lated carrier wave of relatively low frequency. In stand vc'oil arrangement has a low Q which necessitates a high ard television systems the resulting audio modulated car driving power and increases the amplitude of Aharmonics rier wave will have a center frequency of 4.5 mc. The 'which may produce interference in the receiver. Another video and audio signals are thereafter applied to video. disadvantage `is 'that it is diñ‘icult to resonate auxiliary amplifier '16 wherein these signals are amplified and rdeflection coils at frequencies above l0 mc. and the'wobble separated. The video signals are applied to the image re lfpattern’is noticeable at lower frequencies. Additionally, producing device 17 and synchronization signal separator ‘the "auxiliary coil introduces a production problem and 55 18, and the audio modulated carrier wave is ‘applied to diiiiculties may vbe experienced from voltage breakdown the sound discriminator and amplifier 19. The frequency between the auxiliary coils and a conventional deflection modulated audio signals are converted to amplitude modu yoke. Also, if a free running oscillator is utilized in ‘lated signals in the sound signal discriminator and ampli >'the oscillatory circuit it may emphasize the wobble pat fier 19 and after amplification are applied'to sound re Jtern and ­any heterodyne beats because the oscillator may 60 producing unit 20. drift Vcausing these ypatterns to move Vthrough the picture. The synchronization signal separator 13 'removes the The present invention overcomes the above disadvan horizontal and vertical synchronization signals from the tages •‘by Ymeans of a wobble deñection system using an composite video signal and »ampliñes and separates these ‘oscillator in conjunction with electrostatic control grid 52 through a cou trodes known as an electron gun such as that diagramed pling capacitor 55. This positive retrace pulse may be in Fig. l. The electron gun produces and focuses a beam obtained -conveniently from an extra Winding on the hori of electrons which is deflected by means of the deflection zontal output transformer which is part of the horizontal yoke 22 to scan a raster at the target electrode 24 of 10 deflection circuit 23 of Fig. l. The damper tube 50 is picture tube. The electron gun comprises a cathode responsive to the horizontal retrace pulses applied to its electrode`25, a control electrode 26, a screen electrode 27, control grid 52 and the plate current of the damper tube a first anode 2S, a focus electrode 29, and a second anode Si) which is drawn from the oscillator tank 39 causes 30. The focus electrode 29 is divided into two parts, the output of the oscillator to be in synchronism With which are electrically insulated from each other, to form the horizontal retrace pulses. two semicylindrical electrodes 29a and 29h. The elec The circuit shown in Fig. 2 may be simplified if the trode 29 is used to establish the electrostatic field to focus resulting economy justifies the decrease in performance. the electron beam of the picture tube. ln addition, when In a more economical embodiment, the damper tube 50, a voltage difference is applied to the electrodes 29a and resistor 54 and condenser SS may be eliminated. The 29b, the electron beam may be vertically deflected in 20 remainder of the circuit consisting of the oscillator 32, addition to the usual horizontal and vertical deflections split focussing grid 29 and associated components 46, utilized when employing a conventional scan. 47 and. 48 operates to reduce the line structure although The video signals are applied »to the control electrode the oscillator is free running and not phase controlled. Although damper control of the phase is desirable it is 26 and are used to modulate the electron beam of the 25 picture tube 17. A suitable voltage source 31 is provided not as necessary with a high Q split grid wobbler system for supplying focusing voltage for the energization of as with a 10W Q auxiliary coil wobbler because less the focusing electrode 29. The voltage source 31 may harmonic interference is produced by the high Q split be the same voltage source which furnishes a potential grid structure. Although the invention has been described with refer for anode power for the receiving tubes in the receiver. 30 Focus electrode 29 performs as a single piece grid for ence to certain specific embodiments thereof, numerous beam focusing purposes and as a multi-piece grid for modifications falling within the spirit and scope of the invention will be readily apparent to those skilled in this beam deflection purposes. From an appropriate section of the horizontal deflec~ art, after the benefit of the above teachings has been obtained. For example, instead of applying the oscilla tion circuit 23 there is derived a series of pulses which 35 are applied to a damping means 33. The output of the tory deflection voltage to a divided focus electrode, any damping means is applied to the oscillator 32 whose other divided grid of the electron gun may be split invtwo output is, in turn, applied to the focusing electrode 29 or more equal or unequal parts to provide one or more along with the direct current focusing voltage from the sets of auxiliary deflection electrons. Also, if an electro magnetic wobble deflection system is used it is consider focus voltage source 31. 40 Referring now more particularly to the circuit includ ably improved by using the controlled oscillator to gen ing the oscillator 32 and the damping means 33, refer erate the vertical deflection wave applied to an auxiliary ence is made to Fig. 2 in which the oscillator 32 includes coil located around the neck of the picture tube. The an electron tube 34 comprising a plate electrode 36, a damper controlled oscillator will prevent an intereference control grid 37 and a cathode 38; Ia resonant tank cir pattern from moving through the picture. 45 I claim as my invention: cuit 39 comprising an inductance 40 and a condenser 41; l. A cathode ray tube spot wobble deflection system a feedback coupling condenser 42 and a grid return resis comprising, a cathode ray tube comprising a target elec tor 43. One end of the tank circuit 39 is connected to trode and an electron gun arrangement for producing and ground potential while the other end is connected `to cou focusing a beam of electrons, said electron gun arrange pling condenser 42. A tap 44 on the tank inductor 4i) ment including as a part thereof a divided electrode, main is connected to the cathode 3S of oscillator tube 34. The 50 plate 35 of tube 34 is connected to a suitable voltage deflection means for said cathode ray tube, a vertical deflection circuit connected to said main deflection means source B+> and through capacitor 45 to ground potential. fo-r deflecting said beam in a vertical direction across One side 29b of the divided focus electrode 29 is cou ;pled to the grounded end of the oscillator tank 39 by said target electrode at a relatively slow rate, a hori 55 zontal deflection circuit connected to said main deflec means of condenser 46, while the other side 29a of the tion means for deilecting said_beam in a horizontal direc focus electrode 29 is coupled to the ungrounded end of tion across said target electrode at a more rapid rate, the oscillator tank 39 by condenser 47. Resistor 48 and an 'auxiliary vertical deflection circuit connected `to provides a direct current path for the direct current focus said divided electrode for effecting a very rapid deflection sing potential which is applied to the focus electrode 29. 60 of said beam in a vertical direction. The damper 33 is illustrated as an electron tube 50 2. A cathode ray tube spot wobble deflection system having a plate electrode 51, a control grid 52 and a cath comprising, a cathode ray tube comprising a target elec ode 53. The control grid 52 is returned to the cathode trode and an electron gun arrangement for producing and 53 by means of a grid resistor 54. The plate 51 and focusing a beam of electrons, said electron gun arrange cathode 53 of the damper tube 56 are connected across 65 ment including as a part thereof a divided electrode, the tank circuit 39, cathode 53 being connected to the main deflection means for said cathode ray tube, a verti grounded end while the plate 51 is connected to the cal deflection circuit connected to said main deflection ungrounded end. means for deflecting said beam in a vertical direction The oscillator shown in Fig. 2 is a Hartley oscillator. across said target electrode at a relatively slow rate, a It should be understood that other types of oscillators 70 horizontal deflection circuit connected to said main de such as the Cclpitts oscillator may also be used in the flection means for deflecting said beam in a horizontal practice of my invention. Referring now to the operation of the circuit of Fig. 2, direction across said target electrode at a more rapid rate, it is seen that the output of the oscillator 32 is applied and an auxiliary vertical deflection circuit including means across the divided focusing electrode 29 of the picture for maintaining it in synchronism with said horizontal tube. The damper tube 50 is connected across the tank 75 deflection circuit connected to said divided electrode for 2,849,648 5 elîecting a very rapid dellection of said beam in a vertical ing a very rapid deflection of said beam in a vertical di direction. rection in synchronism with said horizontal deflection 3. 'A cathode ray tube spot wobble deflection system circuit, said auxiliary vertical deflection circuit compris comprising, a cathode ray tube comprising a target elec ing an oscillator and damping means for said oscillator trode and an electron gun arrangement for producing connected to said horizontal deñection circuit. and focusing a beam of electrons, main deilection means 6. A cathode ray tube spot wobble dellection com for said cathode ray tube, a vertical deflection circuit prising: a cathode ray tube comprising a target electrode connected to said main deñection means for deilecting and an electron gun arrangement for producing and said beam in a vertical direction across said target elec focusing a beam of electrons, said electron gun arrange trode at a relatively slow rate, a horizontal deflection ment including as a‘part thereof a divided electrode; circuit connected to said main deflection means for de main deflection means for said cathode ray tube; a ver ñecting said beam in a horizontal direction across said tical deilection circuit connected to said main dellection target electrode at a more rapid rate, an auxiliary vertical means for dellecting said beam in a vertical direction deflection means for said cathode ray tube, and an auxil across said target electrode at a relatively slow rate; a iary vertical deflection circuit connected to said horizontal 15 horizontal dellection circuit connected to said main de deilection circuit for applying horizontal retrace pulses llection means for deilecting said beam in a horizontal from said horizontal deflection circuit thereto to main direction across said target electrode at a more rapid _tain said auxiliary vertical deflection circuit in syn rate; and an auxiliary vertical deflection circuit for elfect chronism with said horizontal retrace pulses, said auxil ing a very rapid deflection of said beam in a vertical di iary vertical deflection circuit being connected to said 20 rection comprising, an oscillator having an output con auxiliary vertical deflection means for elfecting a very nected to said divided electrode and control means for rapid dellection of said beam in a vertical direction. said oscillator, a source of horizontal retrace pulses, 4. A cathode ray tube spot wobble dellection system means to apply said horizontal retrace pulses to said con comprising, a cathode ray tube comprising a target elec trol means, said control means being responsive to said trode andan electron gun arrangement for producing and 25 horizontal retrace pulses to produce a control voltage, focusing a beam of electrons, main detlection means and means to apply said control voltage to said oscil for said cathode ray tube, a vertical deflection circuit lator to cause said output of said oscillator to be in syn connected to said main deñection means for deflecting chronism with said horizontal retrace pulses. said beam in a vertical direction across said target elec 7. A cathode ray tube spot wobble dellection system trode at a relatively slow rate, a horizontal dellection 30 comprising: a cathode ray tube comprising a target elec circuit connected to said main deflection means for de trode and an electron gun arrangement for producing flecting said beam in a horizontal direction across said and focusing a beam of electrons; main deflection means target electrode at a more rapid rate, an auxiliary vertical for said cathode ray tube; a vertical deflection circuit deñection means for said cathode ray tube, and an connected to said main deflection means for deilecting auxiliary vertical deflection circuit connected to said aux 35 said beam in a vertical direction across said target elec iliary vertical deñection means for elîecting ‘a very rapid trode at a relatively slow rate; a horizontal deflection cir deflection of said beam in a vertical direction in syn cuit connected to said main deflection means for deflect chronism with said horizontal deflection circuit, said ing said beam in a horizontal direction across said target auxiliary vertical dellection circuit comprising an oscilla electrode at a more rapid rate; an auxiliary vertical de 40 tor and damping means for said oscillator connected to ñection means for said cathode ray tube; and an auX said horizontal deflection circuit. iliary vertical deflection circuit for effecting a very rap 5. A cathode ray tube spot wobble deflection system id dellection of said beam in a vertical direction com comprising, a cathode ray tube comprising a target elec prising, an oscillator having an output connected to said trode on an electron gun arrangement for producing and auxiliary vertical dellection means and control means focusing a beam of electrons, said electron gun arrange~ 45 for said oscillator, a source of horizontal retrace pulses, ment including as a part thereof a divided focusing elec means to apply said horizontal retrace pulses to said con trode, main deflection means for said cathode ray tube, trol means, said control means being responsive to said a vertical dellection circuit connected to said main de horizontal retrace pulses to produce a control voltage, ilection means for deñecting said beam in a vertical di- > and means to apply said control voltage to said oscillator rectíon across said target electrode at a relatively slow 50 to cause said output of said oscillator to be in synchro rate, a horizontal deflection circuit connected to said nism with said horizontal retrace pulses. main deflection means for deñecting said beam in a horizontal direction across said target electrode at a more References Cited in the ñle of this patent rapid rate, and an auxiliary vertical deflection circuit 55 UNITED STATES PATENTS connected to said divided focusing electrode for effect 2,093,157 Nakashima ______Sept. 14, 1937