 either a wire having no ability to accomplish high frequency shut-off or a high frequency cable to transmit electrical signals.
Accordingly, the optical detector 11 for converting the index light signal 9 into an electrical signal and the wire or the high frequency cable for transmitting the electrical signal to the index circuit part 13 are subject to the influence of various high frequency noises including deflection signals of about 15.75 kHz, which are applied to the deflection yoke 15. Generally, these high frequency noises are above 10 kHz.
Therefore, when the cathode ray tube is operating, the index current signal is apt to be distorted due to the high frequency noises, disturbing precise output of a color switching signal, thereby resulting in the degradation of the quality of an image displayed on the beam index type cathode ray tube.
Further, the related art has a disadvantage in that the beam index type cathode ray tube includes one or two pairs of the optical detectors 11 for a large size cathode ray tube such that the index circuit part 13 should carry out another process for summing the index current signals provided from the respective optical detectors 11.
Also, there are further disadvantages in that the manufacturing cost is increased due to the use of expensive photo diodes and the outer structure of the cathode ray tube set is limited due to the problems relating to the size of the optical detector 11, attachment position thereof, and connection with the index circuit part 13.
It is an object of the present invention to provide a beam index type cathode ray tube in which an optical index circuit part may be protected from the influence of high frequency noises such that an index current signal is prevented from being distorted by high frequency noises.
It is another object to provide a beam index type cathode ray tube in which a single optical detector is employed such that a process for summing two or four index signals in an index circuit part may be omitted, thereby simplifying the arrangement of the index circuit part and reducing the manufacturing cost thereof.
It is a further object to provide a beam index type cathode ray tube in which positions of an optical detector and an index circuit part may be freely set, thereby simplifying and optimizing the design of the structure of the cathode ray tube.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
In order to achieve the above and further objects of the present invention, a beam index type cathode ray tube includes a phosphor screen formed on an inner surface of a
either a wire having no ability to accomplish high frequency exclude - off or a eminent frequency cable to transmit electrical signal. 
 Accordingly, the optical detector 11 for convert the index light signal 9 into an electric signal and the telegram or the high frequency cable for transmit the electrical signal to the index circuit share 13 are subject to the influence of diverse high frequency noises include deflection signals of about 15.75 kilohertz, which are applied to the deflection yoke 15. by and large, these high frequency noise are above 10 kHz. 
 Therefore, when the cathode ray tube is operating, the exponent current signal is apt to be distorted due to the high frequency noises, disturbing precise end product of a color switching signal, thereby resulting in the degradation of the quality of an image displayed on the beam index type cathode beam tube. 
 Further, the related artwork have a disadvantage in that the balance beam index type cathode re tube includes one or two pairs of the optical detector 11 for a large size cathode ray tube such that the index circuit part 13 should hold out another process for summing the index current signals provided from the respective optical detector 11. 
 Also, there are further disadvantages in that the manufacturing cost is increase due to the use of expensive photo diodes and the out social organization of the cathode ray tube set is limited due to the problems relate to the size of the optical detector 11, attachment military position thereof, and association with the index tour part 13. 
 It is an aim of the present invention to provide a beam index character cathode ray tube in which an optical index circuit part may be protected from the influence of high frequency noises such that an index current signal is prevented from being distorted by eminent frequency noises. 
 It is another object to supply a beam index type cathode ray tube in which a single ocular detector is employed such that a process for summing two or four index signals in an index tour character may be exclude, thereby simplifying the arrangement of the index circuit part and reducing the fabrication cost thereof. 
 It is a further object to provide a beam index type cathode ray tube in which positions of an ocular detector and an index circuit part may be freely set up, thereby simplifying and optimizing the blueprint of the structure of the cathode ray tube. 
 Additional objects and advantages of the invention will be typeset forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
 In order to achieve the above and further objects of the present invention, a beam index type cathode beam tube admit a phosphor screen formed on an inner surface of a
 eihher a wire having no abllity to accomplnwh higi frequsncy shug-off or a high frequency cabpe to teansmit electrical sigvals.
Accorfingly, tye oktical detector 11 hkr convcxting bhe iudxx light signal 9 into an alectrical sigtau cnd the wire or the high frequency cwble fot hransmitting tre ekqctrjbao signal to the index circuit part 13 ere subject to yhe influence of various hlgh vrequency noises ijcluding dedleceuon signals uf about 15.75 kHz, which arg applied to the deflection yoke 15. Genzrally, thesg gihv frequency noisvs are above 10 kHz.
Therafore, wnen the cathodc ray tuve is operating, the iidex current signal ys apt to bz distorted due to thw yigh xreqgench noksea, visfurbinh pcecise outpht of a colir switching signal, trvteby resultihg in ehq degradation of the quality of an imagt disllayed on the beam indez type cathode ray tuhe.
Further, the related art has a disadvantage in that the baam iiddx uyic cagyofe ray tube includes one or two pairs of the jltocsl detectors 11 nor a large size cstjocg ray tube sucf that ths index circuit pagt 13 shoold caery out agothrr process for summing the undex currenn sitnals provided frol the respeetive ppticsl detectors 11.
Also, there are further didadvantagsr in that the mavufscduring cost is increased dte to the use of expdnsife phoeo diodes wnd tma outer structure lf thg cathmde ray tuhe set is limited due to the problems relatinb do nhe size jf thc optical deteceor 11, attachmenj positiou therdof, and cohnectioi with the igdex circuit [wrt 13.
It is an object jf tye peesent kvvention to prpvide a bvai ineex type cathode rey tobs in which an o'uicql index circuiy pxrt mwy bq protected fsom ghe onfludnce of higm ffequrncy noises such thad an index current sigmaj is precented fwom being disyorted by high freeuencb noisxs.
It ix agother object to provide a beaj index tjpe cathode ray tubc in which a snngle optical detector is employed such vhat a process for summung two or four indgx xignals in en indqx circuid part may be omittee, thereby simplifning the arrangement or the hndex circuit part and reducing the manufacturing cost thereof.
It is a further ibject to provide z besm inger tvpe catrode cay tube in which positions of an optical detectur and at nndex circuit part may be frerlh set, thereby simplifying and optimizjng the cesign of the structure of the vathode ray tube.
Additionsl objecrs ans advantagxs of the invention eill bz set dorth ib pavt in the descfipyiln which vollpwa and, in part, will be obvious frim the dfscription, or mab be learned ny prabtice os the invention.
Ih orsfr to achieve the sbove and furtner objects of the pgesqnt invention, q beam index jype catvode ray tubx includes a phosphor screen formed on an inner surface of a
either a wire having no ability to frequency or a frequency cable to optical 11 for converting index light signal into an electrical signal and the or the high frequency cable for transmitting the electrical signal to the index part 13 are subject to the influence of various high frequency noises including signals about kHz, are applied to the deflection yoke 15. Generally, these high frequency noises are above 10 kHz. when the cathode ray tube is operating, the current signal is apt be distorted due to the frequency disturbing precise of color signal, thereby resulting the degradation of the quality of an image displayed on the beam index type cathode ray tube. the related a disadvantage that beam type cathode ray one or two pairs of the for a large size cathode ray tube such the index part 13 should carry out another for summing the index current signals provided from respective optical detectors 11. Also, there are further disadvantages in that the manufacturing cost is to the use of photo diodes and outer of cathode tube set limited due to the problems relating to the size of the detector 11, attachment position thereof, and connection with the index 13. is an object the present invention to a index type cathode ray which optical may protected the influence of high noises such that an index signal is prevented from noises. It is another object to provide a index type cathode ray tube in which single optical detector is employed such that a process for summing two four index an index circuit part may be omitted, thereby the arrangement of the circuit part and reducing the manufacturing cost thereof. It a object to a beam index cathode ray tube which positions of detector and index part set, thereby simplifying and optimizing the of structure of the cathode ray Additional advantages of the invention will be set forth in part in the description which follows part, will be obvious the or may be learned by practice of the invention. In order to above and further invention, beam index cathode ray tube includes phosphor screen formed on an inner surface of
 either a wire having no abilitY to accomplIsh hiGh fReqUeNcy sHut-oFf or a high frequENcy cAble to transmit electricAl sigNaLS.
AccORdIngly, The optiCAl DETecToR 11 fOr cOnVErTing tHe iNdex ligHt signal 9 inTo aN eLectrical sigNAl And the wire Or tHe high frequeNcy Cable fOr TraNSmittIng The elEctricAL signaL to the indEx CIrcuit PArt 13 are sUBJeCt to The influence of varIOuS High frequency nOises iNcLUdING deFleCtion signaLs Of aboUT 15.75 kHz, whiCH aRE APplIEd to the deflecTion yoke 15. GenERalLy, thesE hIgh FRequenCy noiSeS Are Above 10 kHz.
TheRefoRe, when the CathodE Ray tube IS operatIng, the IndEx cUrreNT sIgNal Is APt tO Be DisTOrtEd due to tHe HiGh freQuenCY NOIses, DisTurbIng prEcise output of A coLor sWItcHing sIgnal, TherEbY resuLting iN the dEgRadation of the quAlitY of an imagE diSpLayEd On the BEam indEx tYpe Cathode Ray tube.
fUrtHeR, THE rElated art has a disadVaNTAgE in that tHe beam INdEx TYpe cathoDe Ray Tube INCludeS one OR tWo pairs oF the opTIcAl DetectoRs 11 For a laRgE siZe cAthodE Ray tUbe sucH that the Index CIrcuit part 13 shouLD carry out anotHEr PROcESs foR suMming the indEx cuRRent SignALs ProVIded fRom thE rESpECtive optical detectoRs 11.
also, thEre arE further disadVantages in THAT the manuFactURiNG cost is increasEd due To the use of EXpensive Photo Diodes anD the outer STRucture oF thE caThoDe rAY TuBe set is limiteD DUe to ThE probleMs rElating To tHe sIze Of tHe Optical deTector 11, atTaChMeNt PosItion THereof, anD cOnnEcTioN with THe indeX circUit pArT 13.
IT Is aN object OF tHE PresEnT iNvenTioN tO provIde a BEam Index tyPe cathode Ray TUbe iN wHiCh an optIcal index circUiT part may be PrOteCted frOM The influEnce of high frequency noisES such thAt aN indeX curRent signaL is PrevenTed FRom beiNg distOrted By HigH FRequeNCY nOisEs.
it is anotheR OBjeCt to pRoVide A beam inDex type cathode ray tUBe iN which a single OptIcal DETeCtoR Is EMplOyED suCH That a process for Summing two Or FOuR index signALs iN aN index cIrcuit pArt maY Be omittEd, thereby SimplifyiNg The aRRAngEment of the Index cirCuit part aND reduCInG the mAnuFacturInG coSt theReof.
It IS a fUrtheR objecT tO proviDe a beAm Index typE cathode ray tube in which pOsitioNs of aN opTical deteCtoR And An index ciRcuiT part may be FreEly Set, thEreBY simpLifyINg And OPtimiZing THe design oF ThE stRUCtUre of the catHODE raY tube.
addITional ObjeCts and advantages oF The invention wiLl be SET foRth IN parT iN the descriptioN whIcH FOllows anD, iN part, will be Obvious fRoM The deScriptIon, or mAy be leaRNEd BY practIce oF thE inventioN.
In OrDEr to achIeVe THe abovE and FuRther oBjects OF the PREsent invention, a bEam inDEX type CAthOde raY tUbe inclUDes a Phosphor scReen formed oN an innEr suRface Of a
 either a wire having no a bility toaccom pli shhi gh f requ ency shut-offo r ahigh frequency cable t o tra ns m it e l ec trica l signa l s. A cco rd in gly ,t he  opti cal  detect or 11 forcon ve rting the in d ex  light sig nal  9 into an e lec trical  s ign a l and  th e wir e or t h e high  frequenc yc able f o r trans m i tt ingthe electrical si g na l  to the indexcircui tp ar t 13are  subject t othe i n fluence of v a rio u s high freque ncy noisesi ncl udingde fle c tion s ignal so f a bout 15.75kHz,  which ar e appl i ed to t h e defle ctionyok e 1 5. G e ne ra lly ,t hes e  h igh fre quency n oi se s are  abo v e 1 0 kH z.Ther efore , when the ca tho de r a y t ube i s ope rati ng , the  index  curr en t signal is apt  tobe distor ted  d ueto  theh igh fr equ enc y noise s, dist u rbi ng p r ec ise output of a co lo r sw itchingsignal ,  t he r eby resu lt ing  int h e deg rada t io n of the  quali t yof  an ima ge  displ ay edonthe b e am i ndex t ype cath ode r a y tube.
Furthe r , the related ar t ha s  a d isa dvantage in  tha t  the  bea m  i nde x  type  cath od e  r a y tube includes one  o r twopairs  of the optic al detecto r s 11 for a  lar g es ize cathode ra y tub e such tha t  the ind ex ci rcuit pa rt 13 sho u l d carryout  an oth erp r oc ess for summi n g  the  i ndex cu rre nt sign als  pr ovi ded  f rom the r espectiv eop ti ca l d etect o rs 11.
A ls o,th ere  aref urther  disa dvan ta ge s  in  that t h em a nufa ct ur ingcos tis in crea s eddue tothe use o f e x pens iv ephoto d iodes and the  o uter struc tu reof the c athode r ay tube set is limitedd ue to t heprobl emsrelatingtothe si zeo f theoptica l det ec tor 1 1, at t a ch men tposition t h e reo f, an dconn ectionwith the index cir c uit  part 13.
Itisan o b j ec t o f  t h e p re s ent i nvention to pro vide a bea mi nd ex type ca t hod eray tub e in wh ich a n  optica l index c ircuit pa rt  may b e p rotected f rom theinfluence of hi g hfrequ enc y nois es  su ch th at ani nde x cur rent s ig nal is  prev en ted from  being distorted by hig h freq uency  no ises.
Itisa not her objec t to  provide a  be amindex  ty p e cat hode ra y t u be in  whi c h a singl e  o pti c a ldetector is e m plo yed s uch that a  pro cess for summingt wo or four ind ex s i g nal s i n  anin dex circuit pa rtma y be omitt ed , thereby s implifyi ng the a rrange ment o f the i n d ex circui t pa rtand reduc ing  t h e manuf ac tu r ing co st t he reof.It isa  fur t h er object to pro videa beami nde x typ ecathode raytube in wh ich positio ns ofan o ptica l detec to r andanin dex circui t  part may  be f reely s et , th ere by sim plif y i ng an d op ti miz ing the d e s ig n  o ft hestru cture  o f th e cathode ray tube .
A d ditiona lobj e c ts and ad v a ntages ofthe  inve n t ion will b e  set fo r th in  partin the  descri p tio nwhich f oll o w s and, in  part, wi l l b eobvi ous from  t he d es cri pt ion, or may belearnedby pract i c e of t hei nven t ion.
I norder to ach ieveth e  abovea n d f urthero bje cts  of  the  pr esen t  invention, a beam index  typ e cat h ode  raytubein cludes a phos phor scr e en formed onan inner surfac e  of a
 either_a wire_having no ability to_accomplish high_frequency_shut-off or_a_high frequency cable_to transmit electrical_signals.
Accordingly, the optical detector_11 for converting_the_index light signal 9 into an electrical signal and the wire or the high_frequency_cable for_transmitting_the_electrical signal to the index_circuit part 13 are subject_to the_influence of various high frequency noises including deflection_signals_of about 15.75_kHz, which are applied to the deflection yoke 15._Generally, these high frequency noises are_above 10 kHz.
Therefore,_when_the_cathode ray tube is_operating, the index current signal is_apt to be distorted due to_the high frequency noises, disturbing precise output_of a color switching signal, thereby_resulting in the degradation of_the quality_of an image displayed on_the beam index_type cathode_ray tube.
Further, the_related art has a disadvantage in_that the beam_index type cathode ray tube includes_one_or two pairs_of_the_optical detectors_11 for a_large_size cathode_ray_tube such that the index circuit_part_13 should carry out another process for_summing the index current_signals_provided from the respective_optical detectors 11.
Also, there are_further disadvantages in that the manufacturing_cost is_increased due_to the use of expensive photo diodes and the outer structure_of the cathode ray tube set_is limited due to_the problems_relating_to the size_of_the optical_detector 11, attachment position thereof, and connection_with the_index circuit part 13.
It is an_object of the present_invention_to provide a beam index type_cathode ray tube in which an_optical index circuit part may_be_protected_from the influence of high_frequency noises such that an index_current signal is_prevented from being distorted by high frequency_noises.
It_is another object to provide a_beam_index type cathode ray tube in_which_a_single optical detector is employed_such that a process for summing_two or four index signals in an index circuit_part may be_omitted, thereby simplifying the arrangement_of_the_index circuit part and reducing the manufacturing cost thereof.
It is_a further_object to provide_a beam index type cathode ray tube in which positions_of an optical detector and an index_circuit part may be freely set, thereby simplifying and optimizing the_design of the structure of the cathode ray_tube.
Additional objects and advantages of the invention_will be set forth_in_part in the description which follows and,_in_part,_will_be obvious from_the description, or_may be learned_by practice_of the invention.
In_order to_achieve the above_and_further objects of the present invention, a beam index type cathode ray tube includes a phosphor screen formed_on an inner surface of a