EP0426237A2 - Procedure for detecting television picture tubes with insufficient vacuum - Google Patents
Procedure for detecting television picture tubes with insufficient vacuum Download PDFInfo
- Publication number
- EP0426237A2 EP0426237A2 EP90202833A EP90202833A EP0426237A2 EP 0426237 A2 EP0426237 A2 EP 0426237A2 EP 90202833 A EP90202833 A EP 90202833A EP 90202833 A EP90202833 A EP 90202833A EP 0426237 A2 EP0426237 A2 EP 0426237A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- tube
- voltage
- tubes
- television picture
- procedure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 12
- 238000004519 manufacturing process Methods 0.000 claims abstract description 8
- 238000005247 gettering Methods 0.000 claims description 4
- 238000001514 detection method Methods 0.000 abstract description 3
- 238000009413 insulation Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 2
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/42—Measurement or testing during manufacture
Definitions
- the invention relates to a method for selecting television picture tubes with too low a vacuum during manufacture.
- it is important to discard all picture tubes with too low a vacuum in good time during the production process so that they are not changed by further production steps, e.g. gettering, in such a way that repairing / regenerating these tubes is made difficult or impossible becomes.
- the invention is therefore based on the object of designing a method of the type mentioned in such a way that it works simply and safely and the selection of the tubes is practically not falsified by insulation currents.
- This object is achieved according to the invention in that between the anode (g4) and a second electrode (g3) of the tube a direct voltage which rises continuously from a low value to a maximum value is applied, the rise of which is stopped when a (spark) or discharge) current flows and the associated value of the DC voltage is evaluated as a criterion for the selection of the tube.
- the insulation currents within the tube base are not included in the measurement result and the measurement circuit can be constructed much more simply, since it is not a small current that has to be measured at a constant applied voltage, but only the point in time (and the associated voltage value) to which a current in the tube begins to flow.
- the focusing electrode (g3) is preferably used as the second electrode.
- the second and all further electrodes are preferably connected to ground potential.
- the figure shows schematically an apparatus for performing the method according to the invention and a television picture tube connected to it.
- the device 1 consists of a voltage generator 2 which generates a DC voltage which rises continuously from a low value to a maximum value and which is applied between the anode (g4) and the focusing electrode (g3) of the tube 4.
- the focusing electrode is connected to earth potential together with all other electrodes (g3) filtered out on the base of the tube.
- a detection circuit 3 is inserted, which emits a signal S in its output as soon as a current flows in the tube between the anode (g4) and the focusing electrode (g3) and causes the voltage U does not continue to rise.
- the voltage U of the voltage generator 2 rises to its maximum value at a rate of approximately 3 kV / sec.
- the voltage U generated by the voltage generator 2 is set such that, at its maximum value (for example 20 kV) in a tube with a good vacuum, no current flows between the anode (g4) and the focusing electrode (g3), which current in the detection circuit 3 leads to a signal at its output S.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
- Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
Abstract
Description
Die Erfindung betrifft eine Verfahren zum Selektieren von Fernsehbildröhren mit zu niedrigem Vakuum während der Fertigung.
Bei der Fertigung von Fernsehbildröhren, insbesondere Farbbildröhren, ist es wichtig, während des Fertigungsablaufes rechtzeitig alle Bildröhren mit zu niedrigem Vakuum auszusondern, damit sie nicht durch weitere Fertigungsschritte, z.B. das Gettern, so verändert werden, daß Reparieren/Regenerieren dieser Röhren erschwert oder unmöglich gemacht wird.The invention relates to a method for selecting television picture tubes with too low a vacuum during manufacture.
In the production of television picture tubes, especially color picture tubes, it is important to discard all picture tubes with too low a vacuum in good time during the production process so that they are not changed by further production steps, e.g. gettering, in such a way that repairing / regenerating these tubes is made difficult or impossible becomes.
Um festzustellen, ob eine Röhre ein zu niedriges Vakuum aufweist ist es bisher üblich, zwischen zwei am Sockel der Röhre herausgeführte Elektroden, z.B. den Gittern (g2) und (g3), eine z.B. pulsförmige Hochspannung anzulegen und den fließenden Ionisationsstrom zu messen.In order to determine whether a tube has a vacuum that is too low, it has hitherto been customary to place between two electrodes led out on the base of the tube, e.g. the grids (g2) and (g3), e.g. to apply pulsed high voltage and measure the flowing ionization current.
Da bei diesem Verfahren in den gemessenen Strom aber die Isolationsströme innerhalb des Sockels der Röhre mit eingehen, arbeitet es verhältnismäßig unzuverlässig.However, since the insulation currents within the base of the tube are included in the measured current in this method, it works relatively unreliably.
Der Erfindung liegt ,daher die Aufgabe zugrunde, ein Verfahren der eingangs genannten Art so auszugestalten, daß es einfach und sicher arbeitet und die Selektion der Röhren durch Isolationsströme praktisch nicht verfälscht wird.The invention is therefore based on the object of designing a method of the type mentioned in such a way that it works simply and safely and the selection of the tubes is practically not falsified by insulation currents.
Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß zwischen der Anode (g4) und einer zweiten Elektrode (g3) der Röhre eine von einem niedrigen Wert bis zu einem Höchstwert kontinuierlich ansteigende Gleichspannung angelegt wird, deren Anstieg gestoppt wird wenn in der Röhre ein (Funken- oder Entlade-)Strom fließt und der zugehörige Wert der Gleichspannung als Kriterium für die Selektion der Röhre ausgewertet wird.This object is achieved according to the invention in that between the anode (g4) and a second electrode (g3) of the tube a direct voltage which rises continuously from a low value to a maximum value is applied, the rise of which is stopped when a (spark) or discharge) current flows and the associated value of the DC voltage is evaluated as a criterion for the selection of the tube.
Bei dem erfindungsgemäßen Verfahren gehen in das Meßergebnis die Isolationströme innerhalb des Röhrensockels nicht ein und die Meßschaltung kann wesentlich einfacher aufgebaut sein, da hier nicht ein kleiner Strom bei einer konstanten angelegten Spannung gemessen werden muß, sondern nur der Zeitpunkt (und der zugehörige Spannungswert) bestimmt werden muß, zu dem ein Strom in der Röhre zu fließen beginnt. Als zweite Elektrode wird vorzugsweise die Fokussierelektrode (g3) benutzt.
Um alle parasitären Ströme sicher auszuschalten, werden vorzugsweise die zweite und alle weiteren Elektroden (außer der Anode) auf Erdpotential gelegt.In the method according to the invention, the insulation currents within the tube base are not included in the measurement result and the measurement circuit can be constructed much more simply, since it is not a small current that has to be measured at a constant applied voltage, but only the point in time (and the associated voltage value) to which a current in the tube begins to flow. The focusing electrode (g3) is preferably used as the second electrode.
In order to safely switch off all parasitic currents, the second and all further electrodes (except the anode) are preferably connected to ground potential.
Besonders vorteilhaft ist est, das erfindungsgemäße Verfahren jeweils vor dem Gettern der Röhre durchzuführen und so Röhren mit zu niedrigem Vakuum rechtzeitig aus dem Fertigungsprozeß herauszunehmen. Diese Röhren können dann gegebenenfalls noch einmel evakuiert werden. Wenn hingegen Röhren mit zu geringem Vakuum gegettert werden, besteht immer die Gefahr, daß Gettermaterial unregelmäßig und unvollständig verdampft. Das Getter wird dann brüchig und führt zu sogenannten "losen Teilen" in der Röhre.It is particularly advantageous to carry out the method according to the invention in each case before gettering the tube and in this way to remove tubes with too low a vacuum from the manufacturing process in good time. These tubes can then be evacuated if necessary. If, however, tubes are weathered with too little vacuum, there is always the risk that getter material evaporates irregularly and incompletely. The getter then becomes brittle and leads to so-called "loose parts" in the tube.
Die Erfindung wird im folgenden anhand der beigefügten Zeichnung in einem Ausführungsbeispiel näher erläutert.The invention is explained in more detail below with reference to the accompanying drawing in one embodiment.
Die Figur zeigt schematisch eine Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens und eine daran angeschlossene Fernsehbildröhre.
Die Vorrichtung 1 besteht aus einem Spannungsgenerator 2, der eine von einem niedrigen Wert bis zu einem Höchstwert kontinuierlich ansteigende Gleichspannung erzeugt, die zwischen der Anode (g4) und der Fokussierelektrode (g3) der Röhre 4 angelegt ist. Die Fokussierelektrode ist dabei zusammen mit allen anderen an den Sockel der Röhre herausgefilterten (g3) Elektroden auf Erdpotential gelegt.
In die Verbindung zwischen Spannungsgenerator 2 und Röhre 4 ist eine Detektionsschaltung 3 eingefügt, die in ihrem Ausgang S ein Signal abgibt, sobald in der Röhre zwischen der Anode (g4) und der Fokussierelektrode (g3) ein Strom fließt und veranlaßt, daß die Spannung U nicht weiter ansteigt.The figure shows schematically an apparatus for performing the method according to the invention and a television picture tube connected to it.
The device 1 consists of a voltage generator 2 which generates a DC voltage which rises continuously from a low value to a maximum value and which is applied between the anode (g4) and the focusing electrode (g3) of the tube 4. The focusing electrode is connected to earth potential together with all other electrodes (g3) filtered out on the base of the tube.
In the connection between voltage generator 2 and tube 4, a detection circuit 3 is inserted, which emits a signal S in its output as soon as a current flows in the tube between the anode (g4) and the focusing electrode (g3) and causes the voltage U does not continue to rise.
Die Spannung U des Spannungsgenerators 2 steigt mit etwa einer Rate von ca. 3 kV/sec auf ihren Höchstwert an. Die von dem Spannungsgenerator 2 erzeugte Spannung U ist so eingestellt, daß bei ihrem Höchstwert (z.B. 20 kV) bei einer Röhre mit gutem Vakuum zwischen der Anode (g4) und der Fokussierelektrode (g3) noch kein Strom fließt, der in der Detektionsschaltung 3 zu einem Signal an ihrem Ausgang S führt.The voltage U of the voltage generator 2 rises to its maximum value at a rate of approximately 3 kV / sec. The voltage U generated by the voltage generator 2 is set such that, at its maximum value (for example 20 kV) in a tube with a good vacuum, no current flows between the anode (g4) and the focusing electrode (g3), which current in the detection circuit 3 leads to a signal at its output S.
Liegt dagegen das Vakuum in der Röhre 4 unter einem vorgegebenen Wert (vor dem Gettern) von etwa 1 bis 20 Pa, so fließt bereits bei einem unter dem Höchstwert liegenden Wert der Spannung ein Strom der zu einem Signal am Selektionsausgang S führt, das dann veranlaßt, daß diese Röhre mit schlechtem Vakuum zunächst aus dem Fertigungsgang entfernt wird.
Auf diese Weise ist es mit einer einfachen Vorrichtung ohne Verfälschung durch Isolationsströme im Sockel der Röhre möglich zu prüfen, ob eine Röhre ein gewisses Mindestvakuum aufweist und Röhren, bei denen dies nicht der Fall ist, zu selektieren.If, on the other hand, the vacuum in the tube 4 is below a predetermined value (before gettering) of approximately 1 to 20 Pa, a current flows at a value of the voltage which is below the maximum value, which leads to a signal at the selection output S, which then triggers that this tube with bad vacuum is first removed from the production process.
In this way it is possible with a simple device without falsification by insulation currents in the base of the tube to check whether a tube has a certain minimum vacuum and to select tubes where this is not the case.
Claims (4)
dadurch gekennzeichnet,
daß zwischen der Anode (g4) und einer zweiten Elektrode (g3) der Röhre eine von einem niedrigen Wert bis zu einem Höchstwert kontinuierlich ansteigende Gleichspannung angelegt wird, deren Anstieg gestoppt wird, sobald in der Röhre ein Funken- oder Entlade-Strom fließt und der zugehörige Wert der Gleichspannung als Kriterium für die Selektion der Röhre ausgewertet wird.1. Method for selecting television picture tubes with too low a vacuum during production,
characterized,
that between the anode (g4) and a second electrode (g3) of the tube, a continuously increasing DC voltage is applied from a low value to a maximum value, the rise of which is stopped as soon as a spark or discharge current flows in the tube and the associated value of the DC voltage is evaluated as a criterion for the selection of the tube.
dadurch gekennzeichnet,
daß als zweite Elektrode die Fokussierelektrode (g3) benutzt wird.2. The method according to claim 1,
characterized,
that the focusing electrode (g3) is used as the second electrode.
dadurch gekennzeichnet,
daß die Fokussierelektrode (g3) und alle weiteren Elektroden (außer der Anode) auf Erdpotential gelegt sind.3. The method according to claim 1 or 2,
characterized,
that the focusing electrode (g3) and all other electrodes (except the anode) are connected to earth potential.
dadurch gekennzeichnet,
daß es vor dem Gettern der Röhren durchgeführt wird.4. The method according to any one of the preceding claims,
characterized,
that it is done before gettering the tubes.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3936015 | 1989-10-28 | ||
DE3936015A DE3936015A1 (en) | 1989-10-28 | 1989-10-28 | METHOD FOR SELECTING TELEVISION TUBES WITH VACUUM TOO LOW |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0426237A2 true EP0426237A2 (en) | 1991-05-08 |
EP0426237A3 EP0426237A3 (en) | 1991-11-21 |
EP0426237B1 EP0426237B1 (en) | 1994-05-18 |
Family
ID=6392473
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP90202833A Expired - Lifetime EP0426237B1 (en) | 1989-10-28 | 1990-10-24 | Procedure for detecting television picture tubes with insufficient vacuum |
Country Status (4)
Country | Link |
---|---|
US (1) | US5083957A (en) |
EP (1) | EP0426237B1 (en) |
JP (1) | JPH03165422A (en) |
DE (2) | DE3936015A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ATE142367T1 (en) * | 1992-12-17 | 1996-09-15 | Philips Electronics Nv | METHOD FOR CURING A FILM |
DE19526394A1 (en) * | 1995-07-19 | 1997-01-23 | Siemens Ag | Vacuum detection system for vacuum switch tube |
US6722184B2 (en) | 2001-09-13 | 2004-04-20 | Guide Corporation | Apparatus and method for pressurized oxygen bulb curing and testing |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1592364A (en) * | 1921-04-26 | 1926-07-13 | Western Electric Co | Ionization manometer |
US4052776A (en) * | 1976-09-30 | 1977-10-11 | Zenith Radio Corporation | Method of spot-knocking an electron gun assembly in a color television picture tube |
JPS63261649A (en) * | 1987-04-20 | 1988-10-28 | Hitachi Ltd | High-voltage processing method for cathode-ray tube |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SU656126A1 (en) * | 1976-06-23 | 1979-04-05 | Рязанский Радиотехнический Институт | Circuit for measuring pressure in sealed gas-discharge devices |
JPS6273526A (en) * | 1985-09-27 | 1987-04-04 | Hitachi Ltd | Method of measuring sealing gas pressure for fluorescent lamp |
US4720652A (en) * | 1987-01-20 | 1988-01-19 | Cooper Industries, Inc. | Sealed beam headlamp and method for testing its serviceability |
-
1989
- 1989-10-28 DE DE3936015A patent/DE3936015A1/en not_active Withdrawn
-
1990
- 1990-10-18 US US07/599,784 patent/US5083957A/en not_active Expired - Lifetime
- 1990-10-24 DE DE59005734T patent/DE59005734D1/en not_active Expired - Fee Related
- 1990-10-24 EP EP90202833A patent/EP0426237B1/en not_active Expired - Lifetime
- 1990-10-25 JP JP2286008A patent/JPH03165422A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1592364A (en) * | 1921-04-26 | 1926-07-13 | Western Electric Co | Ionization manometer |
US4052776A (en) * | 1976-09-30 | 1977-10-11 | Zenith Radio Corporation | Method of spot-knocking an electron gun assembly in a color television picture tube |
JPS63261649A (en) * | 1987-04-20 | 1988-10-28 | Hitachi Ltd | High-voltage processing method for cathode-ray tube |
Non-Patent Citations (2)
Title |
---|
ELECTRONICS Bd. 37, Nr. 1, 3. Januar 1964, MC.GRAW-HILL NEW YORK Seiten 89 - 91; FRED KOHLER: 'PRODUCTION TECHNIQUES TUBE IS OWN VACUUM GAGE ' * |
PATENT ABSTRACTS OF JAPAN vol. 13, no. 81 (E-719)(3429) 23. Februar 1989 & JP-A-63 261 649 (HITACHI LTD ) 28. Oktober 1988 * |
Also Published As
Publication number | Publication date |
---|---|
US5083957A (en) | 1992-01-28 |
JPH03165422A (en) | 1991-07-17 |
DE3936015A1 (en) | 1991-05-02 |
DE59005734D1 (en) | 1994-06-23 |
EP0426237B1 (en) | 1994-05-18 |
EP0426237A3 (en) | 1991-11-21 |
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