US2825849A - Cathode ray tube deflection and high voltage apparatus - Google Patents

Description

March 4, 1958 P. M. LUFKIN ET AL CATHODE RAY TUBE DEFLECTION AND HIGH `V-OLTAGE APPARATUS 2 Sheets-Sheet 1 Filed June 29, 1954 mma :b2 LM L0 l JM Pp mi mnmfu. i... om n MN, Mau in z n mi. e) NW. V H vm N/ 46 7m ,L5 m

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IN VEN TORS P 0L MMF /A/ Aw Bcf/,vais c', Zai/V ,grraf/EY March 4, 1958 P. M. L UFKIN ET A1. 2,825,849

CATHODE RAY TUBE DEFLECTION AND HIGH VOLTAGE APPARATUS Filed June 29', 1954 2 Sheets-Shea?I 2 F 2 .96 A j Hw sa 96 517 fam/if United States Patent Haddon Heights, NJ., assignors to Radio Corporation of America, a corporation of Delaware Applicationv June 29, 1954, serial No. 459,956v claims. (c1. 315-21) The present invention relates to new and improved apparatus for furnishing both the high unidirectional potential for a Icathode ray `tube anode and the electromagnetic energy for causing-an electron beam within such tube to scan a predetermined pattern.

More particularly, this invention relates to an improvement in the well-known combination high voltagev and deection output transformer such employed in conjunction with television receiver kinescopes. t n s Since electromagnetic deflection coils have a certain amount of inductance, some stored energy is present in the coils at the end of each deection cycle. It is possible, through the use of a damping tube `or diode, to use a portion of such stored energy for producingsa part ofthe voltage variations` employed in deecting the cathode ray beam during the initial portion of the next succeeding scanning cycle. Such action is well-known and is termed reaction scanning." The deflection coils also have eertain inherent desirable capacities which, together with their inductance, produce tuned circuits having predeterrnined frequencies. During `the go time, which is the time of the useful trace of the scanning beam, energy is stored in the magnetic field of the transformer and deflection coils. The energy contained in the` coils is permitted to produce a half cycle of free oscillation during the yback time and, at the end of such half cycle of oscillation, the damper diode is employed to control or absorb the remaining energy, whereby to suppress substantially completely the remaining cycles-of oscillation. Since it is desirable that the high voltage or accelerating potential required for operation of the kinescope also be derived in an eflicient manner, it has become customary to combine `the functions of decction and high voltage derivation in a single apparatus in which use is made of the inductive nature of the deection circuits. That is to'say, most present-day television horizontal deection circuits include means such as a power amplifier tube for driving a sawtooth current wave form through a transformer which couples the sawtooth energy to the deflection coils. Through the agency of a voltage step-up winding, the tlyback pulses produced in the circuit inductances during the scanning retrace intervals are applied to a rectifier tube and filtered to alord a high-unidirectional potential for application to the nal anode of the kinescope. Stated otherwise, at the end of the deflection scanning cycle, when the output or power tube is driven to cut-off, whereby the deection voltage source is removed from the coils, the energy contained in the transformer, including the stepup winding, causes relatively higher frequency oscillation to be set up. Such higher frequency oscillation (as distinguished from the desired oscillation which is employed in the retrace deection of the scanning beam) has been the source of such difficulties in practice as the production of raster ringing which manifests itself in the production of alternate dark and light vertical bars, von usually the lefthand side of the raster. In view 'fof as is conventionally I 'ice such undesirable effects which result from velocity modulation of the beam spot intensity, prior workers in the art have proposed many `and varied schemes for reduction of such ringing. The present applicants, on the other hand, have -found that the high frequency ringing may be properly harnessed whereby to aiford increased eticiency in both the deflection and high voltage deriving functions of such apparatus.

lt is a primary object of the present invention, therefore, to provide novel deection and high voltage transformer means for use in high efficiency deection and high voltage production.

By` way of background, and as has been alluded to briefly above, it will be understood that, in the case of the well-known auto transformer arrangement, the damper tube conducts heavily at the end of retrace time, thereby approximating a short circuit across what may be considered as the secondary winding of the transformer. During the latter portion of the scanning period, thehorizontal ,output tube conducts heavily, whereby to approximate a short circuit across what may be considered the primary and secondary portions of the auto transformer. As will be appreciated by those skilled in the art, thereexists a leakage inductance between the high voltage step-up `winding (tertiary winding) and the remaining portion of the auto transformer, which leakage inductance is responsible, at least in part, for the ringing or high frequency oscillation mentioned supra.

The present invention has for another of its objects that of controlling the frequency of the ringing which results from the leakage inductance and its associated inherent capacities in such manner as to provide increased high voltage and greater detlection eiiiciency. p

In general, the present invention provides means fOr controlling the frequency of the described ringing in such manner as to phase the ringing wave form so that the ringing voltage combines with the llyback pulses to increase their amplitude and, secondly, combines with the current through the damper tube in a manner calculated to increase the amount of sawtooth current which may be applied to the system by the power tube, whereby to increase the efficiency of the deection system proportionately. In accordance with the present invention, such control of the ringing frequency is afforded by spacing the tertiary or step-up winding radially from the concentrically wound primary-secondary winding of the autotransformer. This spacing, when of the proper value, decreases the frequency of the ringing in an amount suicient to phase it correctly so as to aid the yback pulses and the deection current.

As will be appreciated, the present invention requires only a simple change in existing deflection and high voltage transformers in order to bring about the improved results set forth herein. Additional objects and advantages of the present invention will become apparent to persons skilled in the art from a study of the following detailed description of the accompanying drawing, in which: n

Fig. l illustrates, by way of block and schematic circuit diagram, a typical television receiver including a combination horizontal deilection and high voltage transformer arrangement in which the present invention may be advantageously employed;

Fig. 2 illustrates certain voltage wave forms to be described; s

Fig. 3 illustrates current wave forms useful in describing another aspect of the invention; and

Fig. 4 is a simplified sectional view of a transformer constructed in accordance with the invention.

Referring to the drawing, and more particularly, to Fig. 1 thereof, block 10 represents that portion of a typical television receiver which includes a radio-freegzeaasan.

The input terminals of receive'r1'0'areprovided-with.

composite televisiony signals which are interceptedrby anuante'nnaflZ.` Thes'evsignls are amplified by fthe r`re ceiver and demodulated in the 'fus'ualmanner so that they appear at output terminal 14, which terminal is; indicated for connection to the beam intensitycontrollingfelectrode of kthe 'cathode Yray image-reproducing device .16.* The video signals demodulated within.thereceiver.10'i-are1or maybe-suitably clipped to 'provide horizontal and' vertical synchronizing pulses" for application ft'o the I sync separafor'l circuit Y18 vi'alead20. The horizontallsync' pulses vlt-hen.'appearing at outputlteriminal '22 -otlthe sync se'partorareapplied for synchronization o'fthe-bruti zontal -deec'tion'sig'nal generator or oscillator?l 24',ki while thevertical"synchronizing pulses are applied via lead26 to 'the vertical-deflection signal generator 28. The` out-A p'ut of`tli`evertical' deflect-ion generator 28 is (min/'en` tionally connected 'fondi-livingthe vertical deflection out` putampliiier'f3'0 which, in turn, drives a suitable'lsawtooth'crret of field frequency through terminalsfY+Y and the vertical ldeiiection lwinding 31.

The otp'ut'o'f the horizontal deliecfion rgenerator 24 is 'coupled to the control electrode 32 of a -horizontal deiie'ction-otput discharge tube 34. Suitable biasing potential' for the discharge tube screen electrode 36 'is'l conventionally supplied from a source of posi` tive potential indicated at terminal 38 as +B througha 'scie/er1 dropping resistor 40 which is, in turn, by-A passedto the" cathode 42 via a capacitor 44. A self-v biasing'cathoderesistor 46 whose value is chosen in'accordarlce with the desired operating bias for amplifier 34is connected in the-cathode circuit of the tube and is bypassed by capacitor 48.

The anodev 50 of amplifier 34 is conneetedto ater- V minal 52 of an auto-transformer 54 which includes an auxiliary step-up winding 56 connected to the anode S8 of'a high-vo`ltage rectifying diode 60. The cathode lila# ment 62 of a'rectit'ier 60, energized by a winding 63 on the transformer`54, is connected to ground through a filter' capacitor 64, so that high voltage for the Vfinal anod'elnot shown)` of k'inescope 16 may be applied to the high-voltage terminal 68. The lower terminus 70 of the' autoltra'nsformer 54 is connected through 'a B` boost capacitor 72 and a linearity control inductance 74 to a source of +B potential at terminal 76.

Another capacitor, such as that indicated at 78,.across which is developed a portion of the B-boost voltage, and which aids in the linearity controlaction of theinductance 74, is directly connected from the auto-transformer terminal 70 to the +B terminal 76. Thehorizontal deflection winding 80 of the cathode ray deflection winding 80 of thecathode ray deection systemis connected in shunt with that portion of the auto-transformer between terminals 79 and 81. The damping device which comprises, by way ofy illustration, the diode 82, is connectedin damping relation with the yoke winding 80 through the -Bboost capacitor 72 andthe'linearityI inductance 74 taken in combination withthecapacitor 78; Accordingly, the anodef84 of-darnper diode 82 isvc'onnected with the +B terminal 76 through the linearity inductance 74, while the diodefcathode 88.is connected to a suitable point 90 on theauto-transformer..

As thus far described,l the apparatus of.` thedrawing is in accordance with conventional practice. ySincethefop,- eration of reaction-scanning,apparatusis well-known, it need not be described in detail here.` A fullanalysis .of such operation'`A is given, for 'exampleyinan article entitled Magnetic Detiection Circuits, RCA Review, September 1947, by O'. H. Schade. Briefly, however, 'it is to be noted that the bias on the horizontal output tube 34 is so adjusted that, during operation, the driving sawtooth waveform 24 which is provided by the horizontal detiection generator, jwill produce anode-cathode conduction during a period corresponding to only a little more 'than half Athe deflectionl cycle. Hence, it :may be assumed that thehorizontaloutput tube'j 34 is rendered conductiveby the sawtooth waveform 24. during only4 that time between` instants vt1 and `tg,during whichi'interval anode-cathode` currentnwilh .passfronl :they .positive power-supply terminal 76 .through the inductance 74 and through the diode 82'to the transformer 54. 'Such current ow inducesLsomeudeectionvoltage and current in the transformer which causes a substantially linear rise in deection current through the yoke winding 80. At timetg, correspondinggto vthe commencement. of'the fretrace intervalr of 'thefdeiiectionlcycle;y the discharge tube .34 becomes non-conductivewandwthe.magnetic.lield in the 'f autoetransformer :and Iyoke thenl collapses, causing oscillation of the primarymesonant. circuit (.i. e. the-r yoke and 'its distributed capacitance) :atits' selffresonantfre quencyV whi'chis normallysat leasttour tofiive times that Tof v.the deflection rfrequency.

yAfterI one-half .cycle .l of .f free foscillation, :the yvoltage appearing across the horizontal winding is of `such polarity vrasl to-rcause the. diode 82v Ltoconduct, thereby damping 'the energymagnetically.v stored in thexyolte; Theidi'rection of the damping current `throughxthezsdiod'e 82,.i'n accordance withy well-knownA reactionziscanning principles, provides-the 'frstportioncf thevsawtooth f throu'ghf the winding' 80, which 'portion' t corresponds f to the-intervalbetween instants' .t3 and "t4iof thesawtooth 24'. By the-time t., vis lreached', the l horizontal'. discharge tube 34@ will have been rendered conductive and thisv time, by reasonoffthefbiasfacrosscapacitors 72 fand78, the diode 82 'willnotv conduct as heavily,ftherebycausing most of "theh'orizontal output tube anode currenttoow through the autoI `transformersection between Vterminals and' 70.

l Also during the'v retrace interval (i. e; between times t2 andt3)` thelcollapse of the magnetic iield in theautotransformer andyoke as abovel described results in the production ofv a high, unidirectional ipulse acrossl the transformerL tertiary wnding-56.v The amplitude of `such pulse ist proportional. tothe `quantity LtV wherer` [j 4is the inductancef of I'the rcircuit and represents` therate` of -change -of'current therein. By virtue ofthevoltagestepmpacton of` the tertiaryfwin'd; ingy56 of'the`trans'formeri54, the pulse is increased in amplitude to provide' additional high voltage potential, after rectification by the diode 60, forthe ltinescopeterm'in'al68. Inaddition to thev desiredvoltage pulse pro'- duced by' thev transformer during the retrace interval, there is additionally produced a ,ringing voltage 'train following the pulse'of a 'frequency .which is determined by 'the' usual formula'A where:Lisltheinductance of thecircuit and'Citscapacityv.incl`uding distributed capacity of'lthetrans'former tertiary winding. Thehigh voltage pulsev and its. associated. ringing voltageisillustrated by. thewave forms .'(z)wand('b),- of.,Fig.-.;2, wherein, .as.,may..b'e. seen,4 the high voltage pulse :96. is.followed by=a ringingvoltage 98'havingfta period equal towfT. Normlllyrfastrnaybe of high voltage which may be obtained and the amount `tof deilection afforded by the circuit.

Referring again to wave form (a) of Fig. 2, it may be seen that the final half cycle of the ringing wave form '9S (i. e. that immediately preceding the second yback high voltage pulse 96') is at or near its minimum value. It has been found through experiment that such phasing of the ringing wave form electively decreases the amplitude of the pulse 96' as through a process in the nature of algebraic subtraction of the voltages. It has been found by the present applicants that, by properly phasing the ringing wave form 98 with respect tothe commencement of the retrace time, it is possible to increase the amplitude of the ensuing high voltage pulse. Specifically, such control of the phasing ofthe ringing waveform 98 is afforded by the `present invention through means for controlling the period of the ringing wave form and changing it from the period T of wave form A(a) to the longer period T `of wave form (b) in Fig. 2. Where the period T' is of the proper value, the nal portion of the ringing voltage train 98 will be at or near its maximum value immediately preceding the cornmencement of the retrace period T1.. With the ringing voltage phased as in wave form (b) of Fig. 2, it effec- -:tively adds to the high voltage pulse 96" to increase its amplitude.

As those skilled in the art will appreciate, it is necessary tto maintain the duration of the retrace interval at its vproper value, so that any arrangement for changing the period of the ringing voltage should be one which prolduces no appreciable difference'in the retrace time. In particular, it has been found by the present applicants .that the period of the ringing voltage train may be increased from its value T to the longer value T' by decreasing the ringing frequency and, specifically, by increasing the leakage inductance between the tertiary winding 56 and the primary winding of the transformer which may be considered as that part between terminals 52 and 70. While it would be possibleto effect such a change in the ringing frequency, for example, by increasing the number of turns of the tertiary coil, thereby increasing the leakage inductance, such an arrangement would be undesirable since it would necessarily increase the distributed capacity of the tertiary winding and, additionally, and even more significantly, would change the turns ratio through which the existing tertiary capacity loading is reected across the deflection winding 80 and, since this transfer is proportional to the square of the number of turns, the retrace time would undesirably be substantially increased. Also, while it is possible to increase the ringing period by adding capacity to the rectier end of the tertiary winding, such an arrangement is impractical since it would increase the retrace time and Vlower the amplitude of the yback pulse.

As may be found in basic text books dealing with matters of the present variety, the leakage inductance between two concentric windings of a transformer is proportional to the quantity where c is the length of a turn midway between innermost and outermost layers, a is the distance between the two windings, conductor to conductor, d1 and d2 are the build-ups of the two windings (all of the foregoing dimensions being expressed in inches) and N is the number of turns of the winding to which the leakage inductance `is referred. Since the build-up d1 of the primary winding of the transformer 54 inV Fig." 1V is nor.-

mally" fixed -by 'such considerations as the primary im-l pedance direct current resistance, tiux density in the core and minimum primary-to secondary leakage inductance, the present invention affords a control of the leakage inductance of the tertiary'winding with respect to the rest of the winding by changing the parameter a, namely, the distance measured radially between' the windings. As may 'be determined from the foregoing expression for leakage inductance, the leakage inductance is therefore increased as a direct function of the spacing between the tertiary winding and the remainder of the transformer and, secondarily, by the increase in the mean winding diameter (referring to the parameter c). At the same time, as will be understood from the following formula, the distributed capacity of the tertiary winding is increased only by the increase in the mean diameter of the tertiary winding:

where c is the mean length of turn of the winding; l is the length of winding (i. e. wire traverse); d is the distance betweenl layers (all in inches); T is the number of layers of wire in the winding; and k is the average dielectric `constant of the insulation material. Since the turns ratio is not increased, however, and since the change in the radial spacing parameter a produces only` a small amount of additional capacitive loading, the present invention affords the desired increase in the ringing frequency without changing the length of retrace time appreciably. Y

Fig. 4 illustrates by way of a simplified, vertical sectional vlew, a combination deilection and high voltage transformer such as that illustrated schematically in the circuit diagram of Fig. l and, in the interest of clarity, reference numerals identical to those used in Fig. l designate corresponding portions of the structure of Fig. 4. In Fig. 4, the transformer 54 includes a first winding from lterminal 52 to the terminal 70 which comprises the primary winding of the transformer. This winding is cylindrically arranged about a cylinder 100 formed of a suitable insulating material.y An iron core in the form of two C-shaped members 102 and 104 4is provided in a conventional manner. `The ends of the C-shaped members 102 and 104 within the insulating cylinder or coil form 100 may be spaced, as shown, for the purpose of eliminating saturation due. to plate `current (D. C.) flowing from terminal to terminal 52. The tertiary winding 56 starts at the point 52 and ends at the lead 106 which is adapted for connection to the anode 58 ofthe lhigh voltage rectifier diode 60 and is suitably coated with insulating material 107. The tertiary winding 56 is wound concentrical-ly with respect to the primary winding and, in accordance with the present invention, is spaced therefrom a predetermined distance a by means of an insulating spacer 108 of the proper thickness. The spacer may, for example, be made of such material as a phenol formaldehyde resin. Normally, as will be recognized by those skilled in the art, the aim of transformer designers in the past has been that of winding the tertiary or step-up winding as close to the primary winding as is possible since the concern was with reducing the leakage inductance as much as possible in an effort to decrease the ringing. In accordance with the present invention, however, the additional spacing member 108 for spacing the tertiary winding 56 from the primary winding by a predetermined distance a is employed for the express purpose of increasing the leakage inductance between the two windings in such manner as .to increase the period 'of the ringing voltage attributable to the leakage inductance, whereby to phase the ringing voltage with respect to the commencementxof the retrace interval as shown in wave form (b) of Fig. 2. The specific values of the various physical' dimensions of thetransformerwlndings will, of course, vary as a func- 7 tion ot':the"desirednamplitudmoiideflection tand: the.` vlliex ofc the. high'l voltage...to ..;he;,;pr.od1uce.d: 'In/cih' oteproviding;a,ispecicxampla.beweren th .fallen/lus; dimensiensoff-an;actual transfQrmer.;bui1.t.-iu accordeur.s2i` with theinventien ,for-.use in .@7051 deiiect-io. kilovoltrhightvoltage arrangement are: herein presented), asrfollows:

Inner diameter of .theprimarywinding (i. et outer diameter'of-fthecoil form100)`=01550l 1 v i ference between'its-outerfandinnerf.diameters)i=0.080f^ Fiom. the .-foregona-.itmarb eenhat the spacing member 1.08 entrapment-invent. .eases .thegleakags inductance between the tertiarywindrngjand the primary winding of the transformer '4i`n such manner as to decrease the ringingfrequencyt Such nvijxjequency decrease may be selected, moreover; to be ofthe proper amount for phasingthe ringing voltage as shown. in wave form; (Iz). of. Fig. 2. so that the ringing voltage. is atror near itsl maxi. mumpeak value yat the commencementof theretrace interval.

Although the followingidoes not specifically. constitute a part of the present invention, 'it should be. noted'in the interest of completeness'of description that the ring',- -ing effect upon the .deflection linearity is mini-mizedj'in accordance with Ithe circuitry ofiFig.' 1A by virtue of the connection of the lower. end ,of the horizontal deflection winding 80 at the point 719-0n the transformer r54, 4which point isr spaced in potential from the-bottonr of the winding (terminal 70) or A. Cl ground'. This connection of the-deflection winding atahi'gherimpedancepoint than groundis alwell-knowny expedient forereducingthe effects of ringing upon deflection linearity and is-effective in ythe casel of the present invention wherein the leakage inductancebetween the 'tertiary Aandl primary windings of the `transformer is intentionallyincreased for the purposes set forth.

Another important-advantageaiorded by the present invention, as stated supra, is that of increasing the 4etliciency of the deflection circuit itself; Brey, this action is accomplished by virtue of the -fact thatthe spacing between the tertiary and' primary -windingsof'the transformer-also changes the phase of the leakage inductance ringing voltagewhich `is coupled Vinto the damper tube circuit. Specifically, and as is-well-known, the amount of horizontal` driving voltage which may beimpressed upon. the deflection transformer 54 bythe horizontal-'output 'tube 34 is limited lbythe damper tube current. That is to say, maximum permissible drive -isnormally attained when the-damper tube current isreducedy to zero in the vicinity of the middle of the scanning line, such cessation of dampertube conduction beingmanifested by a bright vertical line in the center of the kinescope raster. As stated above .in connection with ythe lgeneral description of the deflection circuitvoperation, it is the damper tube current (between times t3 and t4) which furnishes approximately half of the deection `energy in each horizontal line scan. It'has beenfoundy that, for optimum performance of such a react-ion scanning arrangment to be realized, it *is necessary forthedriver tube 34 to furnish an excess of current to thedeflecti-on circuits, so that the -damper Ytube may conduct continf uously during the go time. A typical current wave form through a damper tube .such asthe tube `82 kin Fig. 1 is illustrated by Wave form (a) ofvFig; 3, in which the go time;or scanning Vperiod .isdesign-ated as T539 By virtue -of the connection of thesd-amper diode as shown, current therethrough is in the negative direction as is necessitatedby the requirementthat the'damper current dellect thegelectron beam 'within-.theikinescope to thecpposite side Aof its -central positionffrom-that direction in which the driver-tube current deectsit. The dotted line portion 112 of the-.zdamper-currenttwav :Lild .is Areduce rinsing; 9i siy .serein fl'ssiueilsy; .ansimeans for from the leakage indnctarrce-of`thev transformer whichy i.s.;9.11nlsf;l iii-ta the. damper-tube. circuit. 'The .minima or. peaks... llnqffthedsiiipr tube .surfent wave faim.

-h ndisdieats demper tubs limiting. sgndiien. fer the L sy.. bis. furnished. bythe tubs. 34. .Sincethe stlsisasy Qfglh. Circuitis generally :lr0- ncstinnalf ,Qfiflrive Whisihjissy be sills.- cessful'ly.appliedtotlrecircuit, it ishdesirable to increase the surrsntftlirpueli fhg/.d

` amperjtube (i. e .in the nega tive.. direti'olr.. S9. 'that ,the .Peaks .1116' is 110i 'fss'sh lsf@ or,v` stated-otherwisesofthatdthe damper tube isnotfcut oifduring the mridt'ller'o-f` the',scanning'-liue. The present invention performs thev desirable functiolnho'f increasing the'damper tube current during the middle portion of theiscanningV line by sok phasing the. ringing voltage train of the leakagepinductance that'it adds 'to the damper tube'eurrentA in such mannernas to increase that current (injits negative direction) b y adding a negative half cycle ofthering'ingf energy 'to tlhe damper tube current during-the central part ofthe scanning line interval, thereby preventingthe-rdamper tube current from being cutfoi.- yThegphasing of-the ringing voltage as .accomplished in the-l interest `off-increasing the amplitude of the highvoltage pulsesihasbeen found tobe substantially. the proper phase for increasing the damper tubecu-rrent duringthefrniddleroffthe scanningline, `and as illustrated in'4 waveform..(bymiFig. v3. That is .to say, the spacing ofLthetertiary-.winding.56 from, the primary winding of thettran'sformcn 54=which increases the leakageinductance therebetweemwhereby to `increase .the period of the ,ringe inglvoltageftrain provides anegative half cycle of ring-A ing .voltage near: the peaks. Q fythedamper current ways form .of Eig. 3(4).. so ythat .the l,resultant .damper current is.. chsngedto thatshqwalzyrwave form .(b) 9i Fie. 3 wherein the freak 1.1.16]-- mere. nsgstirs than the, zere reference Thun. the @meant of drive which may bs furnished hy the lisrizqaisl .output tubs 34 is increased .Sather greater dstlessnesiensy is psssible yPisom th f reigning, it vwill be understood that `the '4 t1l provijdes` a novel combination high volt- .sllsstisnftrarlsfsrm ,in which the high vsliup Windisch srasediadillvfrm the primary windingl van, a, nt .sufficient to increase the yleakage inductance between. ith'etwo, windings .in such manner'as to-change therhase offtllsleskage ringing voltage train connection to an electromagnetic deflection winding; a

second transformer winding'electrically connected serially with and physically concentric with respect tto Asaid first winding,insuchymanperras to be in energy transfer relationship therewith, said second winding having au ,output terminal, f9.1' snnnestiou .to a ,reciifying .Circuit of Atheftype, adapted to rectify recurrent yback voltage impulses-preda d. ilssaid.- transformer whsssby mpio.- .stisnal potential fps .srplisstifn .l0 l .ssidtrsnsfsrmsr .having inherent liyitsigsm .arsssnant circuit-with sli@ snee oi--saiiitransisrmer 0f .such Character .as .l0

` minal adapted for connection to such spacing said second winding radially outwardly from said first winding a substantial distance greater than the minimum distance and suicient to increase the leakage inductance between said first and second winding by such an amo-unt as to decrease said certain frequency by a predetermined amount.

2. A combined deflection and high voltage transformer for use in conjunction with a cathode ray tube, said transformer comprising: a first transformer winding having an input terminal adapted for connection to a source of deflection energy and a pair of output terminals for connection to an electromagnetic deflection winding; a second transformer winding electrically connected serially with and physically concentric with respect to said first winding in such manner as to be in energy transfer relationship therewith, said second winding having an output terminal for connection to a rect-ifying circuit of the type adapted to rectify recurrent yback voltage impulses produced in said transformer whereby to produce a high, unidirectional potential for application to such cathode ray tube, said second winding having inherent capacity and leakage inductance between said second winding and said first winding of a certain value forming a resonant circuit with said capacity whereby ringing is produced at a given frequency determined by the values of said leakage inductance and said inherent capacity; and means for spacing said second winding radially from said rst winding by a predetermined substantial distance greater than the minimum distance such that said leakage inductance is increased in an amount sufficient to decrease said given ringing frequency by a predetermined amount.

3. A combined deflection and high voltage transformer for use in conjunction with a cathode ray tube, said transformer comprising: a first transformer winding having an input terminal adapted for connection to a source of deflection energy and a pair -of output terminals for connection to an electromagnetic deflection winding; a second transformer Winding electrically connected serially with and physically concentric with respect to said rst winding in such manner as to be in energy transfer relationship therewith, said second winding having an output terminal for connection to a rectifying circuit of the type adapted to rectify recurrent yback voltage impulses produced in said transformer whereby to produce a high, unidirectional potential for application to such cathode ray tube, said second winding having inherent capacity and leakage inductance between said second winding and said lirst winding of a certain value forming a resonant circuit with said capacity whereby generally sinusoidal ringing is produced at a given frequency determined by the values of said leakage inductance and said inherent capacity, said given frequency being such that said ringing is in a certain phase relationship with respect to such flyback impulses; and means for spacing said second winding radially from said first winding by a predetermined substantial distance greater than the minimum distance such that said leakage inductance is increased in an amount sufficient to decrease said given frequency by a predetermined amount whereby to alter said phase relationship between said ringing and such llyback impulses.

4. A combined high voltage and deection transformer for use in conjunction with a cathode ray tube reaction scanning circuit of the type including driver means for furnishing a sawtooth current waveform during a portion of the scanning time and a unilaterally conductive damper device for furnishing deflection current during the remainder of the scanning time, and in such manner that such damper device current reaches a minimum value at a certain point in the scanning cycle, said transformer cornprising: a first transformer winding having an input terv driver means, a pair of 'output terminals for connection to an electromagnetic deflection winding; and a terminal for connection to such damper device; a second transformer winding electrically in series with and physically concentric with respect to said first winding in such manner as to be in energy transfer relationship therewith, said second winding having an output terminal for connection to a rectifying circuit of the type adapted to rectify recurrent yback voltage irnpulses produced in said transformer whereby to produce a high, unidirectional potential to such cathode ray tube, said second winding having inherent distributed capacity and leaking inductance between said second winding and said first Winding of a certain value forming a resonant circuit with capacity whereby generally sinusoidal ringing is produced at a given frequency determined by the values of said leakage inductance and said inherent capacity, said given frequency being such that said ringing is in a certain phase relationship with respect to such damper current minimum value; and means for spacing said second winding radially from said first winding by a predetermined substantial distance greater than the minimum distance such that said leakage inductance is increased by an amount sufficient to decrease said given ringing frequency by a predetermined amount whereby to alter said phase relationship between said ringing and such damper current.

5. A combined high voltage and deflection transformer for use in conjunction with a cathode ray tube reaction scanning circuit of the type including driver means for furnishing a sawtooth current waveform during a portion of the scanning time and a unilaterally conductive damper device for furnishing deection current during the remainder of the scanning time, and in such manner that such damper device current reaches a minimum value at a certain point in the scanning cycle, said transformer comprising: a first transformer winding having an input terminal adapted for connection to such driver means, a pair of output terminals for connection to an electromagnetic deflection winding; and a terminal for connection to such damper device; a second transformer Winding electrically in series with and physically concentric with respect to said first winding in such manner as to be in energy transfer relationship therewith, said second Winding having an output terminal for connection to a rectifying circuit of the type adapted to rectify recurrent yback voltage irnpulses produced in said transformer whereby to produce a high, unidirectional potential to such cathode ray tube, said second winding having inherent distributed capacity and leakage inductance between said second winding and said first winding of a certain value forming a resonant circuit with capacity whereby generally sinusoidal ringing is produced at a given frequency determined by the values of said leakage inductance and said inherent capacity, said given frequency being such that said ringing is in a certain phase relationship with respect to such damper current minimum value; and means for spacing said second winding radially from said first winding by a predetermined substantial distance greater than the minimum distance such that said leakage inductance is increased by an amount sufficient to decrease said given ringing frequency by a predetermined amount whereby to alter said phase relationship between said ringing and such damper current so that said ringing increases such minimum value of damper current.

References Cited in the le of this patent UNITED STATES PATENTS 2,476,164 Von Ingren Schenau July 12, 1949 2,476,854 Friend July 19, 1949 2,513,160 Friend June 27, 1950 2,611,106 Fyler et al. Sept. 16, 1952 2,639,319 Torsch May 19, 1953 2,668,911 Schlesinger Feb. 9, 1954 2,678,413 Adler et al. May 11, 1954

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