DK148868B - DEMAGNETIZING DEVICE, NAMELY FOR COLOR IMAGE DRIVERS - Google Patents
DEMAGNETIZING DEVICE, NAMELY FOR COLOR IMAGE DRIVERS Download PDFInfo
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- DK148868B DK148868B DK067780AA DK67780A DK148868B DK 148868 B DK148868 B DK 148868B DK 067780A A DK067780A A DK 067780AA DK 67780 A DK67780 A DK 67780A DK 148868 B DK148868 B DK 148868B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/003—Arrangements for eliminating unwanted electromagnetic effects, e.g. demagnetisation arrangements, shielding coils
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/16—Picture reproducers using cathode ray tubes
- H04N9/29—Picture reproducers using cathode ray tubes using demagnetisation or compensation of external magnetic fields
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2229/00—Details of cathode ray tubes or electron beam tubes
- H01J2229/0007—Elimination of unwanted or stray electromagnetic effects
- H01J2229/0046—Preventing or cancelling fields within the enclosure
- H01J2229/0053—Demagnetisation
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- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Video Image Reproduction Devices For Color Tv Systems (AREA)
- Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Description
i 148868in 148868
OISLAND
Nærværende opfindelse vedrører en indretning til afmagnetisering af farvebilledrør, der har en magnetisk afskærmning, ved hjælp af en som en enhed udformet afmagnetiseringsspole i en skrå eller skæv stilling, hvilken afmagnetise-5 ringsindretning er af den i krav l's indledning angivne art.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for demagnetizing color image tubes having a magnetic shield by means of a unit-designed demagnetizing coil in an oblique or oblique position, which demagnetizing device is of the kind set forth in claim 1.
Farvefjernsyn vises ofte ved hjælp af skyggemaskebil-ledrør. I sådanne rør bliver en mangfoldighed af elektronstråler fra lidt forskellige udgangspunkter rettet imod en skærm, der er dækket med fluorescerende lysstofmaterialer.Color television is often shown using shadow mask articulated tubes. In such tubes, a variety of electron beams from slightly different starting points are directed at a screen covered with fluorescent fluorescent materials.
10 Lysstoffet er grupperet i triader eller grupper på tre, hvis enkelte "medlemmer" hvert lyser med sin særlige primærfarve, når det rammes af elektronstrålen. Hvert medlem af hver triade er ved hjælp af en skyggemaske indrettet til at påvirkes af én bestemt af de mange elektronstråler. Skyggema-15 sken er en tynd .ledende skærm med en mængde huller nøjagtigt anbragt i forhold til hver triade af farvelysstofpletter.10 The light substance is grouped into triads or groups of three whose individual "members" each glow with its particular primary color when hit by the electron beam. Each member of each triad is arranged by means of a shadow mask to be influenced by one determined by the many electron beams. The shadow mold is a thin conductive screen with a plurality of holes exactly positioned relative to each triad of color light stains.
I idealtilfældet tillader skyggemasken at lysstofpletten for hver enkelt farve bliver belyst udelukkende af en elektronstråle kommende fra en bestemt position. Når tre elek- ΛΛ tronstråler udgår fra lidt forskellige udgangspunkter.Ideally, the shadow mask allows the bright spot for each color to be illuminated solely by an electron beam coming from a particular position. When three electron beams start from slightly different starting points.
Vil hver af farvelyspletterne i en trio således, være· ren, dvs. belyst af kun én elektronstråle, og variationer i farver kan opnås ved passende styring af elektronkilden.Thus, each of the color light spots in a trio will be · clean, ie. illuminated by only one electron beam, and color variations can be achieved by appropriate control of the electron source.
Tidligere var farvefjernsynsskærme følsomme over for 25 indflydelsen fra jordens magnetfelt. Det magnetiske felt, der passerede gennem billedrøret, afbøjede elektronstrålerne bort fra deres tilsigtede baner og ændrede den tilsyneladende kilde for de til skyggemasken kommende elektronstråler på en måde, der afhang af billedrørets orientering 30 i forhold til jordens magnetiske felt, så farverenheden blev forringet. Tidligere forsøg på at løse dette problem omfattede brug af feltneutraliserende viklinger som beskrevet i US-patentskrift nr. 2 921 226(Vasilevskis). I den feltneutraliserende indretning føres en j.ævnstrøm gennemIn the past, color television screens were sensitive to the influence of the Earth's magnetic field. The magnetic field passing through the image tube deflected the electron beams away from their intended trajectories and altered the apparent source of the electron beams coming to the shadow mask in a manner that depended on the orientation of the image tube 30 relative to the Earth's magnetic field so that the color unit deteriorated. Previous attempts to solve this problem included the use of field neutralizing windings as described in U.S. Patent No. 2,921,226 (Vasilevskis). In the field neutralizing device, a DC current is passed through
Off én eller flere spoler, der er anbragt omkring billedrøret, på en sådan måde, at de udbalancerer eller neutraliserer jordens magnetfelt. Dette krævede indstilling af fagfolk, og fornyet indstilling, hvis fjernsynet blev flyttet til et nyt sted.Off one or more coils disposed around the image tube in such a way as to balance or neutralize the earth's magnetic field. This required the setting of professionals, and renewed setting if the television was moved to a new location.
2 148868 O Et andet forsøg på at løse de farverenhedsproblemer, der opstår på grund af jordens magnetfelt, omfattede brugen af magnetiske afskærmninger. I en sådan indretning omgiver en hul skærm med form som en afkortet kegle det rum, hvorigennem elektronstrålen passerer på vej til 5 skyggemasken og skærmen. Skærmens høje permeabilitet leder udefra kommende magnetiske felter bort fra elektronstrålen.2 148868 O Another attempt to solve the color unit problems that occur due to the Earth's magnetic field included the use of magnetic shields. In such a device, a hollow screen shaped like a truncated cone surrounds the space through which the electron beam passes on its way to the shadow mask and screen. The high permeability of the screen directs external magnetic fields away from the electron beam.
Det viste sig imidlertid, at den permeable magnetiske skærm kunne blive magnetiseret og, når dette var sket, selv forstyrre farverenheden · Afmagnetiseringsindretninger blev så ]_q opfundet til at afmagnetisere skærmen og skyggemasken.However, it appeared that the permeable magnetic screen could be magnetized and, when this happened, even interfere with the color unit. · Demagnetizers were then invented to de-magnetize the screen and shadow mask.
Afmagnetiseringen bliver udført ved at sende en vekselstrøm med stor begyndelsesamplitude gennem en eller flere spoler, der er anbragt omkring skyggemasken og den magnetiske skærm, som beskrevet i US-patentskrift nr. 2 962 621 (Pernald).The demagnetization is performed by passing an alternating current of high initial amplitude through one or more coils disposed around the shadow mask and magnetic screen, as described in U.S. Patent No. 2,962,621 (Pernald).
15 Størrelsen af vekselstrømmen formindskes derpå langsomt til nul, og magnetiseringen af skærmen reduceres derved.15 The magnitude of the alternating current is then slowly reduced to zero and the magnetization of the screen is thereby reduced.
En spole, der er anbragt langs periferien af skyggemasken som vist af Pernald, er tilbøjelig til at frembringe et relativt lille magnetfelt nær midten af skyggemasken.og 2o skærmen. Såledeser det nødvendigt med en strøm, der kan være upraktisk stor, for at afmagnetisere med en sådan spole.A coil disposed along the periphery of the shadow mask as shown by Pernald tends to produce a relatively small magnetic field near the center of the shadow mask.and 2o screen. Thus, a current that may be impractically large is required to de-magnetize with such a coil.
For at øge den magnetiske flux gennem den magnetiske skærm og gennem skærmen uden for store viklingsstrømme, blev der opfundet indretninger, som dem, der er beskrevet i 25 US-patentskrift nr. 3 322 998 (Norley) og 3 872 347 (Matsushima). I Norley og Matsushima-indretningerne ligger et par spoler symmetrisk på billedrøret, idet hver vikling har en del liggende langs skyggemaskens periferi og en del, der strækker sig imod rørets hals. Denne indretning med to 3Q spoler frembringer et magnetfelt, hvis feltlinier går hen over eller på tværs af rørets længdeakse. Denne løsning med et "tvær-aksiålt" afmagnetiseringsfelt, der frembringes af to spoler, tilvejebringer en effektiv afmagnetisering. Imidlertid kræver disse to spoler yderligere . mon-35 teringsarbejde, sammenlignet med en enkelt spole, og deres indbyrdes forbindelse kan give anledning til forkert ledningsføring. Desuden kræver indretningen med to spoler enIn order to increase the magnetic flux through the magnetic screen and through the screen outside large winding currents, devices such as those described in 25 U.S. Pat. Nos. 3,322,998 (Norley) and 3,872,347 (Matsushima) were invented. In the Norley and Matsushima devices, a pair of coils lie symmetrically on the image tube, each winding having a portion lying along the periphery of the shadow mask and a portion extending towards the neck of the tube. This device with two 3Q coils produces a magnetic field whose field lines extend across or across the longitudinal axis of the tube. This solution with a "cross-axial" demagnetization field produced by two coils provides efficient demagnetization. However, these two coils require further. assembly work, as compared to a single coil, and their interconnection may give rise to incorrect wiring. In addition, the two-coil arrangement requires one
OISLAND
3 148868 større lederlængde end indretningen med en enkelt spole, og den kan reagere på afbøjningsågfeltet med strømme, der forstyrer farverenheden.3 148868 greater conductor length than the single coil device and can respond to the deflection saw field with currents interfering with the color unit.
Det er opfindelsens formål at anvise en afmagneti-5 seringsindretning, hvori der anvendes en som en enhed udformet spole, og som behøver en forholdsvis kort lederlængde, der frembringer en afmagnetiseringspåvirkning i det væsentlige svarende til, hvad der opnås med indretningen med to spoler, men i det væsentlige uden at afbøjningsågets 10 strømme fremkalder farverenhedsforstyrrende strømme i afmagnetiseringsindretningen, kombineret med den enkle udformning og korte lederlængde, der kendes fra indretninger med en enkelt spole.It is an object of the invention to provide a demagnetizing device using a unitary coil which needs a relatively short conductor length which produces a demagnetizing effect substantially similar to that achieved with the two coil device, but substantially without the currents of the deflection saw 10 causing color unit interfering currents in the demagnetizer, combined with the simple design and short conductor length known from single coil devices.
Det angivne formål opnås med en afmagnetiseringsind-15 retning af den indledningsvis omhandlede art, som ifølge opfindelsen er ejendommelig ved den i krav l's kendetegnende del angivne udformning.The stated object is achieved with a demagnetizing device of the kind initially referred to, which according to the invention is characterized by the design according to the characterizing part of claim 1.
På tegningen viser fig. la og lb i perspektiv et billedrør med en afmag- 20 netiseringsindretning ifølge opfindelsen, fig. 2a og 2b set bagfra henholdsvis fra siden den i fig. la og lb viste indretning, fig. 3 et tværsnit af det i de foregående figurer viste billedrør, 25 fig. 4b magnetiske feltfordelinger i indretningen ifølge opfindelsen, fig. 4a og 4c magnetiske feltfordelinger svarende til den tidligere teknik, og fig. 5 er et blandet billed-, koblings- og blok-30 diagram, der belyser opfindelsens anvendelse i en fjernsynsmodtager.In the drawing, FIG. 1a and 1b are a perspective view of a picture tube with a de-energizing device according to the invention; FIG. 2a and 2b, respectively, from the side view, respectively, of the one shown in FIG. 1a and 1b, FIG. 3 is a cross-sectional view of the picture tube shown in the previous figures; FIG. 4b magnetic field distributions in the device according to the invention; 4a and 4c are magnetic field distributions similar to the prior art, and figs. 5 is a mixed image, coupling and block diagram illustrating the use of the invention in a television receiver.
I figur la og lb omfatter et billedrør, som helhed betegnet med 10, et hylster bestående af tre forskellige dele. En keglestub- eller pyramideformet del 12a er ved keg-35 lestubdelens smalle ende forbundet med en del 12b af hylstrets hals. En udfladet forpladedel 12c lukker keglestub- 4 148868 o delen 12a's brede ende. En fod 14 på den ende af halsdelen 12b, der ligger fjernt fra keglestubdelen, bærer ben, ved hvis hjælp der dannes forbindelser med elektronkanonbat-teriet, der er monteret inden i halsdelen 12b. En høj-5 spændingsanode- eller ultorforbindelsesknap 16 er anbragt på overfladen af keglestubdelen 12a. En afmagnetiserings-spole, der som helhed er betegnet med 20, er anbragt på den ydre overflade af hylstret 12. Spolen 20 har stort set form som en afrundet trekant. Et stykke 20a på spolen 20 10 ligger nær ved periferien af forbindelsen mellem hylstrets forplade 12c og keglestubdelen 12a. Yderligere stykker 20b og 20c af spolen 20 danner et toppunkt, der strækker sig hen imod og rundt om forbindelsen mellem hylstrets hals-og keglestubdelene. Et par ledninger 22 er ført fra spolen 20 15 til forbindelse med en ikke vist kilde, ved hjælp af hvilken en strøm med variabel amplitude føres gennem spolen 20 med henblik på afmagnetiseringen.In Figures 1a and 1b, a picture tube, generally denoted by 10, comprises a casing consisting of three different parts. A cone-shaped or pyramid-shaped part 12a is connected at the narrow end of the cone-piece to a part 12b of the neck of the sleeve. A flattened face portion 12c closes the cone stub wide end 12a. A foot 14 on the end of the neck portion 12b, remote from the cone stub portion, carries legs by means of which connections are made with the electron gun battery mounted within the neck portion 12b. A high voltage anode or ultor connection button 16 is arranged on the surface of the cone stub portion 12a. A demagnetizing coil, generally designated 20, is disposed on the outer surface of the casing 12. The coil 20 is generally shaped like a rounded triangle. A portion 20a of the coil 20 10 is adjacent to the periphery of the connection between the casing front plate 12c and the cone stub portion 12a. Additional pieces 20b and 20c of the coil 20 form a vertex extending towards and around the connection between the neck and cone stub portions of the sleeve. A pair of wires 22 is routed from coil 20 15 to a source not shown by means of which a variable amplitude current is passed through coil 20 for de-magnetization.
Figur 2a og 2b viser henholdsvis bagfra og fra siden det i fig. la og lb viste arrangement. Bagsidebilledet i 20 figur 2a viser den i nogen grad rektangulære kontur af den brede ende af keglestubdelen, der er fælles for de for tiden almindeligt anvendte billedrør. Halsdelen derimod er cirkulær, som det ses på bagsidebilledet for at lette monteringen af afbøjningsåg og andre til halsen hørende 25 komponenter.Figures 2a and 2b show, respectively, from behind and from the side that in fig. 1a and 1b. The back view of Figure 2a shows the somewhat rectangular contour of the wide end of the cone stub common to the currently used imaging tubes. The neck portion, on the other hand, is circular, as seen in the rear view to facilitate the mounting of deflection saws and other 25 component parts.
Det som set ovenfra viste snit gennem billedrøret 10 i figur 3 viser en lysstofskærm 330, liggende nær ved indersiden af hylstrets forplade 12c. En skyggemaske 332 er monteret nar lysstoflaget 330 ved hjælp af monterings-30 konsoller 334 og 336. Monteringskonsollerne 334 og 336 understøtter også en hul magnetisk skærm 338, der er udformet af magnetisk permeabelt materiale. Skærmen 338 er fortrinsvis stort set formet som keglestub'délen 12a af billedrøret 10's hylster. Både den brede og den smalle ende 35 af skærmen 338 er åbne for at tillade passage af en eller flere elektronstråler fra et elektronkanonbatteri 340, der er monteret indeni halsdelen 12b, imod lysstoflaget 330.The sectional view, as seen from above, through the picture tube 10 in Figure 3 shows a fluorescent screen 330, located near the inside of the cover plate 12c of the housing. A shadow mask 332 is mounted near the luminous layer 330 by means of mounting brackets 334 and 336. The mounting brackets 334 and 336 also support a hollow magnetic shield 338 formed of magnetically permeable material. The shield 338 is preferably substantially shaped as the cone stub portion 12a of the sleeve of the image tube 10. Both the wide and the narrow ends 35 of the screen 338 are open to allow passage of one or more electron beams from an electron gun battery 340 mounted inside the neck portion 12b toward the luminous layer 330.
5 148868 o5 148868 o
Retningen af den magnetiske feltfordeling, der dannes af en afmagnetiseringsspole, der er monteret koncentrisk med billedrøret, er vist i snit i figur 4a. Ved en afprøvning af en sådan indretning var størrelsen af det op-5 nåelige afmagnetiseringsfelt ved centrum af skærmen 332 0,2 gauss med en spole, der maksimalt'.kunne give 20 gauss.The direction of the magnetic field distribution formed by a demagnetization coil mounted concentrically with the image tube is shown in section in Figure 4a. In testing such a device, the size of the attainable demagnetization field at the center of the screen 332 was 0.2 gauss with a coil that could provide a maximum of 20 gauss.
Spolen dannede også mellem 0,3 og 0,6 gauss ved periferien af åbningen ved dens smalle ende eller indgangsenden af den magnetiske skærm 338.The coil also formed between 0.3 and 0.6 gauss at the periphery of the aperture at its narrow end or the input end of magnetic shield 338.
10 I modsætning hertil har indretningen ifølge opfin delsen som sin kerne mere af den magnetiske skærm 338 og danner en feltfordeling nogenlunde som vist i figur 4b.In contrast, the device of the invention, as its core, has more of the magnetic shield 338 and forms a field distribution roughly as shown in Figure 4b.
Midten af skærmen befinder sig i et område med større feltstyrke. Ved at bruge en afmagnetiseringsspole, der frem-15 bringer det samme maksimumsfelt som den i figur 4a, opnåedes et afmagnetiseringsfelt ved midten af skærmen på 0,5 gauss, hvilket er næsten dobbelt så meget som med den tidligere teknik. De tilsvarende feltstyrker ved indgangsenden på den magnetiske skærm 338 var 7,5 gauss ved siden nærmest spolen, 20 1 gauss ved siden fjernest fra spolen og 4 gauss ved de andre to sider. Således er de felter, der står til rådighed for afmagnetisering af skærmen, meget større ved indretningen ifølge opfindelsen end i den i figur 4a viste, når spolerne har det samme amperevindingstal.The center of the screen is in an area of greater field strength. By using a demagnetization coil that produces the same maximum field as the one in Figure 4a, a demagnetization field at the center of the screen of 0.5 gauss was obtained, which is almost twice that of the prior art. The corresponding field strengths at the input end of magnetic screen 338 were 7.5 gauss next to the coil, 20 1 gauss next to the coil and 4 gauss at the other two sides. Thus, the fields available for demagnetizing the screen are much larger in the device according to the invention than in the one shown in Figure 4a when the coils have the same ampere recovery number.
25 Figur 4c viser den magnetiske feltfordeling ved indretninger med to spoler, såsom ifølge Norley og Matsushima. I den i figur 4c viste indretning frembringer den kombinerede effekt af spolep^-rreten betydelig magnetfeltf lux på tværs af billedrørets akse i området ved den 30 magnetiske skærm 338. Ved rørets forplade- og skyggemaske-ende er de magnetiske feltlinier parallelle med skyggemasken og er tilbøjelige til at have en ensartet styrke gennem midten af skyggemasken. Den afmagnetisering, der tilvejebringes ved hjælp af opfindelsen, er i det væsentlige 35 ækvivalent med dén, der opnås ved hjælp af den i figur 4c viste indretning med to spoler, idet den tilvejebringer afmagnetisering for den indvendige magnetiske skærm såvel som for. maske- og rammeaggregatet. Afmagnetiseringsindret- o 6 148868 ningen ifølge opfindelsen er billigere/ idet den behøver kortere ledere end både den i figur 4a viste indretning med en enkelt spole og indretninger med to spoler. Indretningen ifølge opfindelsen er lettere at samle end indretnin-5 gerne med to spoler og kan ikke tilsluttes forkert.Figure 4c shows the magnetic field distribution of two-coil devices, such as according to Norley and Matsushima. In the device shown in Figure 4c, the combined effect of the coil tube produces significant magnetic field flux across the axis of the image tube in the region of the magnetic screen 338. At the front and shadow mask ends of the tube, the magnetic field lines are parallel to the shadow mask and are likely to have a uniform strength through the center of the shadow mask. The demagnetization provided by the invention is substantially equivalent to that obtained by the two coil arrangement shown in Fig. 4c, providing demagnetization for the internal magnetic shield as well as for. the mask and frame assembly. The demagnetizing device according to the invention is cheaper / in need of shorter conductors than both the single coil device shown in Figure 4a and the two coil devices. The device according to the invention is easier to assemble than the devices with two coils and cannot be connected incorrectly.
Figur 5 viser en kreds, i hvilken afmagnetiseringsspolen kan strømforsynes med en vekselstrøm med stor begyndelsesamplitude, der aftager til i det væsentlige nul.Figure 5 shows a circuit in which the demagnetization coil can be supplied with a high initial amplitude alternating current which decreases to substantially zero.
I figur 5 omfatter en del af fjernsynsmodtageren et stik 10 510 til forbindelse med et vekselstrømsnet. En afbryder 512 og smeltesikring 514 forbinder nettet med primærviklingen 516a på en effekttransformator 516. En sekundærvikling 516b på transformatoren 516 frembringer en vekselstrøm, der udnyttes af en energiforsyning, der er vist som en blok 518, 15 til strømforsyning af resten af fjernsynsmodtageren, der er vist som en blok 520. Vekselstrømskilden er også gennem en temperaturfølsom modstand 530 forbundet med Sp51en..220 Ls tilledninger 222. Den temperaturfølsomme modstand 530 har en positiv temperaturkoefficient, således at modstanden i 20 thermistoren er lav ved stuetemperatur og stiger med stigende temperatur.In Figure 5, a portion of the television receiver comprises a connector 10 510 for connection to an AC network. A switch 512 and fuse 514 connect the mains to the primary winding 516a of a power transformer 516. A secondary winding 516b of the transformer 516 generates an alternating current utilized by an energy supply shown as a block 518, 15 to power the remainder of the television receiver. shown as a block 520. The AC source is also connected through a temperature sensitive resistor 530 to the Sp51..220 Ls wires 222. The temperature sensitive resistor 530 has a positive temperature coefficient so that the resistance of the thermistor is low at room temperature and increases with increasing temperature.
Ved stuetemperatur er modstanden i thermistoren 530 lav. Når afbryderen 512 er sluttet for at strømforsyne fjernsynsmodtageren, tilføres energien gennem transforma-25 toren 516 til energiforsyningen 518 for at strømforsyne modtageren. På samme tid påtrykkes en vekselspænding over serieforbindelsen mellem thermistoren 530 og spolen 220.At room temperature, the resistance of the thermistor 530 is low. When the switch 512 is connected to power the television receiver, the energy is supplied through the transformer 516 to the power supply 518 to power the receiver. At the same time, an alternating voltage is applied across the series connection between thermistor 530 and coil 220.
Fordi modstanden i thermistoren 530 er lille i starten, flyder en relativt stor vekselstrøm gennem spolen 220.Because the resistance of the thermistor 530 is small at first, a relatively large alternating current flows through the coil 220.
30 Strømmen gennem thermistoren 530 opvarmer thermistoren, og dermed stiger dens modstand. Den stigende modstand formindsker den strøm, der skyldes den påtrykte vekselspænding, og kompenserer delvis for den reducerede afsatte effekt i thermistoren ved den formindskede strøm. Tempera-35 turen i thermistoren fortsætter med at stige og bevirker en hurtig reduktion af strømmen til en lille grænseværdi, når 730 Current through the thermistor 530 heats the thermistor, thus increasing its resistance. The increasing resistance reduces the current due to the applied AC voltage and partially compensates for the reduced deposited power in the thermistor by the reduced current. The temperature of the thermistor continues to rise and causes a rapid reduction of current to a small limit value when 7
OISLAND
148868 modstanden af thermistoren når sit maksimum. Et kredsløb, der udnytter temperaturfølsomme modstande (thermistorer), er beskrevet i US-patentskrift nr. 4 024 427 (Belhomrae).148868 the resistance of the thermistor reaches its maximum. A circuit utilizing temperature-sensitive resistors (thermistors) is described in U.S. Patent No. 4,024,427 (Belhomrae).
Selv om der i den beskrevne indretning er anvendten 5 indre magnetisk skærm, vil fagfolk på området kunne indse, at opfindelsens principper er ligeså anvendelige på bil-ledrør, der er udstyret med en ydre skærm.Although in the disclosed device, an internal magnetic shield is used, those skilled in the art will appreciate that the principles of the invention are equally applicable to automotive articulated tubes equipped with an outer shield.
Claims (3)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US1281079A | 1979-02-16 | 1979-02-16 | |
| US1281079 | 1979-02-16 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| DK67780A DK67780A (en) | 1980-08-17 |
| DK148868B true DK148868B (en) | 1985-10-28 |
| DK148868C DK148868C (en) | 1986-04-21 |
Family
ID=21756797
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DK67780A DK148868C (en) | 1979-02-16 | 1980-02-15 | DEMAGNETIZING DEVICE, NAMELY FOR COLOR IMAGE DRIVERS |
Country Status (20)
| Country | Link |
|---|---|
| JP (1) | JPS55112087A (en) |
| KR (1) | KR900006295B1 (en) |
| AT (1) | AT381201B (en) |
| AU (1) | AU535877B2 (en) |
| BE (1) | BE881758A (en) |
| CA (1) | CA1135321A (en) |
| DE (1) | DE3005763C2 (en) |
| DK (1) | DK148868C (en) |
| ES (1) | ES8100551A1 (en) |
| FI (1) | FI70357C (en) |
| FR (1) | FR2449382B1 (en) |
| GB (1) | GB2046559B (en) |
| HK (1) | HK27284A (en) |
| IT (1) | IT1140569B (en) |
| MY (1) | MY8500294A (en) |
| NZ (1) | NZ192884A (en) |
| PL (1) | PL126142B1 (en) |
| SE (1) | SE441886B (en) |
| SU (1) | SU936835A3 (en) |
| ZA (1) | ZA80875B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IN167955B (en) * | 1986-03-27 | 1991-01-12 | Nokia Data Systems |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2921226A (en) * | 1956-05-24 | 1960-01-12 | Philco Corp | Apparatus for color purity correction in color television receivers |
| US2962621A (en) * | 1958-10-10 | 1960-11-29 | Westinghouse Electric Corp | Color television apparatus |
| US3322998A (en) * | 1964-08-31 | 1967-05-30 | Rca Corp | Color purity correcting apparatus for colored television picture tubes |
| US3614519A (en) * | 1967-12-18 | 1971-10-19 | Zenith Radio Corp | Cathode-ray tube magnetic shield |
| US3872347A (en) * | 1972-04-14 | 1975-03-18 | Tokyo Shibaura Electric Co | Degaussing device for colour cathode ray tubes |
| NL167289C (en) * | 1973-09-13 | 1981-11-16 | Philips Nv | COLOR TELEVISION DEVICE EQUIPPED WITH A COLOR TELEVISION IMAGE TUBE AND DEMAGNETIZING DEVICE. |
| NL165020C (en) * | 1974-12-16 | 1981-02-16 | Philips Nv | COLOR TV RECEIVER CONTAINING A DEMAGNETIZER CIRCUIT AND COMPOSITE THERMISTOR ELEMENT FOR USE IN SUCH A CIRCUIT. |
| JP3016048B2 (en) * | 1991-12-04 | 2000-03-06 | 東洋自動機株式会社 | Temperature control method for impulse sealing device |
-
1980
- 1980-02-08 FI FI800394A patent/FI70357C/en not_active IP Right Cessation
- 1980-02-08 AU AU55357/80A patent/AU535877B2/en not_active Ceased
- 1980-02-08 SE SE8001035A patent/SE441886B/en not_active IP Right Cessation
- 1980-02-12 IT IT19868/80A patent/IT1140569B/en active
- 1980-02-12 GB GB8004693A patent/GB2046559B/en not_active Expired
- 1980-02-14 JP JP1771880A patent/JPS55112087A/en active Pending
- 1980-02-15 BE BE0/199427A patent/BE881758A/en not_active IP Right Cessation
- 1980-02-15 CA CA000345759A patent/CA1135321A/en not_active Expired
- 1980-02-15 DE DE3005763A patent/DE3005763C2/en not_active Expired
- 1980-02-15 SU SU802885001A patent/SU936835A3/en active
- 1980-02-15 PL PL1980222054A patent/PL126142B1/en unknown
- 1980-02-15 KR KR1019800000615A patent/KR900006295B1/en active
- 1980-02-15 NZ NZ192884A patent/NZ192884A/en unknown
- 1980-02-15 FR FR8003444A patent/FR2449382B1/en not_active Expired
- 1980-02-15 DK DK67780A patent/DK148868C/en not_active IP Right Cessation
- 1980-02-15 ES ES488650A patent/ES8100551A1/en not_active Expired
- 1980-02-18 AT AT0088580A patent/AT381201B/en not_active IP Right Cessation
- 1980-09-17 ZA ZA00800875A patent/ZA80875B/en unknown
-
1984
- 1984-03-22 HK HK272/84A patent/HK27284A/en not_active IP Right Cessation
-
1985
- 1985-12-30 MY MY294/85A patent/MY8500294A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| HK27284A (en) | 1984-03-30 |
| NZ192884A (en) | 1983-11-18 |
| KR900006295B1 (en) | 1990-08-27 |
| CA1135321A (en) | 1982-11-09 |
| PL126142B1 (en) | 1983-07-30 |
| FI800394A (en) | 1980-08-17 |
| FI70357C (en) | 1986-09-15 |
| AU5535780A (en) | 1980-08-21 |
| SU936835A3 (en) | 1982-06-15 |
| SE8001035L (en) | 1980-08-17 |
| PL222054A1 (en) | 1980-11-03 |
| ES488650A0 (en) | 1980-11-01 |
| SE441886B (en) | 1985-11-11 |
| JPS55112087A (en) | 1980-08-29 |
| BE881758A (en) | 1980-05-30 |
| FI70357B (en) | 1986-02-28 |
| DK67780A (en) | 1980-08-17 |
| IT1140569B (en) | 1986-10-01 |
| ES8100551A1 (en) | 1980-11-01 |
| DE3005763C2 (en) | 1984-11-15 |
| GB2046559B (en) | 1983-04-20 |
| FR2449382B1 (en) | 1985-11-22 |
| AT381201B (en) | 1986-09-10 |
| DK148868C (en) | 1986-04-21 |
| GB2046559A (en) | 1980-11-12 |
| IT8019868A0 (en) | 1980-02-12 |
| ATA88580A (en) | 1986-01-15 |
| FR2449382A1 (en) | 1980-09-12 |
| ZA80875B (en) | 1981-08-26 |
| DE3005763A1 (en) | 1980-08-28 |
| AU535877B2 (en) | 1984-04-12 |
| MY8500294A (en) | 1985-12-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PBP | Patent lapsed |