CA1149857A - Getter construction for reducing the arc discharge current in color tubes - Google Patents
Getter construction for reducing the arc discharge current in color tubesInfo
- Publication number
- CA1149857A CA1149857A CA000341366A CA341366A CA1149857A CA 1149857 A CA1149857 A CA 1149857A CA 000341366 A CA000341366 A CA 000341366A CA 341366 A CA341366 A CA 341366A CA 1149857 A CA1149857 A CA 1149857A
- Authority
- CA
- Canada
- Prior art keywords
- getter
- side wall
- upraised
- wall member
- ray tube
- 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.)
- Expired
Links
Classifications
-
- 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
- H01J29/94—Selection of substances for gas fillings; Means for obtaining or maintaining the desired pressure within the tube, e.g. by gettering
Landscapes
- Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
- Common Detailed Techniques For Electron Tubes Or Discharge Tubes (AREA)
Abstract
D-12,312-C
IMPROVED GETTER CONSTRUCTION FOR REDUCING
THE ARC DISCHARGE CURRENT IN COLOR TV TUBES
Abstract of the Disclosure Getter assembly for television picture tubes which minimizes arcing currents in a television picture tube comprising a solid center getter container having a relatively high outside wall and having wire support mem-bers located entirely beneath the getter container.
S P E C I F I C A T I O N
S P E C I F I C A T I O N
IMPROVED GETTER CONSTRUCTION FOR REDUCING
THE ARC DISCHARGE CURRENT IN COLOR TV TUBES
Abstract of the Disclosure Getter assembly for television picture tubes which minimizes arcing currents in a television picture tube comprising a solid center getter container having a relatively high outside wall and having wire support mem-bers located entirely beneath the getter container.
S P E C I F I C A T I O N
S P E C I F I C A T I O N
Description
~ ~ ~9 ~ 57 The present invention is directed to a getter assembly for use in television picture tubes. More particularly the present invention is directed to a getter assembly which functions to minimize potentially destructive electrical arc curr~ents in television picture tubes.
The problem of electrical arcs and arc currents in television picture tubes is well known and described in detail in the prior art, for example U.S Patent 4,101,803 (1978). As noted in this patent and elsewhere in the prior art, conductive coatings provided on the inside and outside of the funnel portion of television picture tubes constitute a large capacitor which filters the high voltage which is applied to the screen of the television picture tube. The inner conductive coating is at the same potential as the screen and transmits the scraen voltage to the neck of the picture tube where it is applied, e.g., by spring contacts, to a high voltage anode electrode at the forward part of the electron gun. The ~20 various electrodes in the electron gun are closely spaced and at widely different electric p~tentials.
This circumstance, as is well known,results in arcing between the electrodes in the event that foreign parti-culate matter occurs in an inter-electrode space or if there is an improperly spaced electrode. In the event ~ ~ ~9 ~ 57 of an arc, the filter capacitor formed by the conductive coatings on the inside and outside portions of the picture tube funnel dumps its enormous s~ored charge within a few microseconds resultin~ in instantaneous currents on the order of hundreds of amperes and higher which can cause destruction of associated circuitry.
A known technique for reducing the magnitude of the arc currents is to employ a resistive coating on the inner surface o~ the picture tube funnel, e.g., composition containing metal oxide, e.g., iron oxide.
The resistivity of such coatings is relatively high, on the order of 2,000 to 6,000 ohms per square, and the arc current can be reduced on that account. However, in the gettering of television picture tubes, as is known to the art, a film of barium metal is deposited on portions of the inner funnel surface overlying the resistive coating and, at times, can provide a low resistance path and essentially short circuit the ~ resistive coating.
: 20 It is accordingly an object of tha present invention to provide a getter assembly which avoids the deposition of a short circuit barium film.
Other objects will be apparent from the following description and claims taken in conjunction with the drawing wherein ~9B57 ;
Figure 1 shows a tele~vision picture tube having a getter in accordance wi.th the present invention incorporated therein Figures 2(a)-2(d) show representative elevation - and plan views of the ~etter of the present in~ention Figure 3 is a perspective view of the getter support member of the present invention, and Figure 4 illustrates the distribution of getter mat~rial using a getter in accordance with the present invention.
- With reference to Figure 1 of the drawing, a television picture tube is indicated at I0 having a glass funnel portion 12 joined to neck 14. An electron gun assembly is schematically indicated at 16. An outer conductive coating is provided at 18 and a resistive inner conductive coating is provided at 20. A high voltage is conventionally applied to the resistive inner coating through anode button 22. The above-noted inner and outer coatings constitute a filter capacitor.
A getter assembly is provided as shown at 24 mou~ted on elongated metal spring member, or "antenna"
26 which is attached at 28 to electron gun 16 whereby a path is provided for the transmission of the high voltage ~ . -on resistive coating 20 to the electron gun 16. This path is incidental to the main high voltage path which is via snubber spring contact ~7. When the getter 24 of the present invention is "flashed" the vaporized getter material, e.g., barium, is deposited in ~he funnel portion 12 as indicated at 30 and bridges a portion of resistive coating 20. If this "bridging"
coating of barium were to c~ntact the support member 32 of getter assembly 24, a short circuit of resistive coating 20 would occur in the event of an arc condition.
However, in the practice of the present invention as hereinaflter more fully described, the barium film 30 is not deposited in the resion 34 where the getter support member 32 contacts resistive coating 20.
With reference to Figures 2(a)-2(d) the getter assembly of the present invention comprises a cylindrical getter container or receptacle 40 suitably made of stainless steel having an upraised bottom portion 42 which forms an annular open top channel 44 in which is pressed getter material 46 in the usual manner, e.g., for example 1000 mg. of 25% Ba~ 25% Al, 50% Ni exothermic alloy yielding about 225 mg. of Ba on "flashing". The side wall 48 which joins floor member 50 of channel 44 is substantially greater in height than upraised portion 42 with respect to floor member 50, e.g., 1.5 to 5 ~imes :. . . . .
~;1985~7 greater in height, preferably about 2 times greater in height. Antenna mount 26 is joined to the floor member 50 by spot welds at 52. Wire support member 60, shown in perspective in Figure 3, and with reference to Figures 2(a)-(d), comprises a length of small diameter, e.g., 0.045 inch wire having for convenience a flattened middle portion and having end portions 68, 71 both bent inwardly toward each other. These end portions are bent first downwardly and thenupwardly to form curved bases 70, 72. The wire support member 60 is arranged perpen-dicularly to antenna support 26 and fastened at its flattened midpoint 62 by a spot weld. The wire support member 60 will thus depend downwardly from the bottom of metal receptacle 40 with the curved bases 70, 72 entirely beneath the floor member 50 and spaced inwardly from side wall member 48 toward the upraised portion 42, preferably about midway between the side wall member 48 and upraised portion 42. On account of the above-described configuration, upon "flashing" of getter material 46, the vaporized metal wiIl not deposit in region 34 shown in Figures 1 and 4 due to the substantially higher side wall 48 and since region 34 is essentially "shadowed"
against the gletter material vapor by the flow member 50 of receptacle 40. Thus, the inwardly curved base `
` - 12312 ~ 57 portions 70, 72 rest in resistive re~ion 34 spaced from getter metal film 30.
By way of specific example a getter assembly in accordance with the presPnt i~vention was made with a container of 305 stainless stelel having an outer diameter of 0.765 in. The height of the container sides was 0.165 in., the width of the getter channel floor was 0.238 and the height of the upraised center portion was 0.076 in. The wire support was formed of 0.045 in. diameter 305 stainless steel wire and held the floor of the getter eontainer 0.155 in. from the inner surface of the picture tube when installed.
Getter material (25% Ba, 25% Al, 50% Ni) in the amount of i,000 mg. was pressed in the channel of the getter.
Using getters of the above type in accordance with the present invention arc current was reduced in tests to about 60 amperes from about 600 amperes which resulted when getters were used which did not have the combination o~ high side walls and "shadowed" support member.
In some applications, the height 77 of wire support member 60 is reduced so that the bottom of receptacle 40 is closer than usual (0.155 inch) to the funnel portion of the picture tube, e.g., about .. . .
~9t3~7 (0.130 to 0.150 inch), in order to enchance the 'l~hadowing"
efect.
- - 8 - ;
.. ' - , . ~.
.
The problem of electrical arcs and arc currents in television picture tubes is well known and described in detail in the prior art, for example U.S Patent 4,101,803 (1978). As noted in this patent and elsewhere in the prior art, conductive coatings provided on the inside and outside of the funnel portion of television picture tubes constitute a large capacitor which filters the high voltage which is applied to the screen of the television picture tube. The inner conductive coating is at the same potential as the screen and transmits the scraen voltage to the neck of the picture tube where it is applied, e.g., by spring contacts, to a high voltage anode electrode at the forward part of the electron gun. The ~20 various electrodes in the electron gun are closely spaced and at widely different electric p~tentials.
This circumstance, as is well known,results in arcing between the electrodes in the event that foreign parti-culate matter occurs in an inter-electrode space or if there is an improperly spaced electrode. In the event ~ ~ ~9 ~ 57 of an arc, the filter capacitor formed by the conductive coatings on the inside and outside portions of the picture tube funnel dumps its enormous s~ored charge within a few microseconds resultin~ in instantaneous currents on the order of hundreds of amperes and higher which can cause destruction of associated circuitry.
A known technique for reducing the magnitude of the arc currents is to employ a resistive coating on the inner surface o~ the picture tube funnel, e.g., composition containing metal oxide, e.g., iron oxide.
The resistivity of such coatings is relatively high, on the order of 2,000 to 6,000 ohms per square, and the arc current can be reduced on that account. However, in the gettering of television picture tubes, as is known to the art, a film of barium metal is deposited on portions of the inner funnel surface overlying the resistive coating and, at times, can provide a low resistance path and essentially short circuit the ~ resistive coating.
: 20 It is accordingly an object of tha present invention to provide a getter assembly which avoids the deposition of a short circuit barium film.
Other objects will be apparent from the following description and claims taken in conjunction with the drawing wherein ~9B57 ;
Figure 1 shows a tele~vision picture tube having a getter in accordance wi.th the present invention incorporated therein Figures 2(a)-2(d) show representative elevation - and plan views of the ~etter of the present in~ention Figure 3 is a perspective view of the getter support member of the present invention, and Figure 4 illustrates the distribution of getter mat~rial using a getter in accordance with the present invention.
- With reference to Figure 1 of the drawing, a television picture tube is indicated at I0 having a glass funnel portion 12 joined to neck 14. An electron gun assembly is schematically indicated at 16. An outer conductive coating is provided at 18 and a resistive inner conductive coating is provided at 20. A high voltage is conventionally applied to the resistive inner coating through anode button 22. The above-noted inner and outer coatings constitute a filter capacitor.
A getter assembly is provided as shown at 24 mou~ted on elongated metal spring member, or "antenna"
26 which is attached at 28 to electron gun 16 whereby a path is provided for the transmission of the high voltage ~ . -on resistive coating 20 to the electron gun 16. This path is incidental to the main high voltage path which is via snubber spring contact ~7. When the getter 24 of the present invention is "flashed" the vaporized getter material, e.g., barium, is deposited in ~he funnel portion 12 as indicated at 30 and bridges a portion of resistive coating 20. If this "bridging"
coating of barium were to c~ntact the support member 32 of getter assembly 24, a short circuit of resistive coating 20 would occur in the event of an arc condition.
However, in the practice of the present invention as hereinaflter more fully described, the barium film 30 is not deposited in the resion 34 where the getter support member 32 contacts resistive coating 20.
With reference to Figures 2(a)-2(d) the getter assembly of the present invention comprises a cylindrical getter container or receptacle 40 suitably made of stainless steel having an upraised bottom portion 42 which forms an annular open top channel 44 in which is pressed getter material 46 in the usual manner, e.g., for example 1000 mg. of 25% Ba~ 25% Al, 50% Ni exothermic alloy yielding about 225 mg. of Ba on "flashing". The side wall 48 which joins floor member 50 of channel 44 is substantially greater in height than upraised portion 42 with respect to floor member 50, e.g., 1.5 to 5 ~imes :. . . . .
~;1985~7 greater in height, preferably about 2 times greater in height. Antenna mount 26 is joined to the floor member 50 by spot welds at 52. Wire support member 60, shown in perspective in Figure 3, and with reference to Figures 2(a)-(d), comprises a length of small diameter, e.g., 0.045 inch wire having for convenience a flattened middle portion and having end portions 68, 71 both bent inwardly toward each other. These end portions are bent first downwardly and thenupwardly to form curved bases 70, 72. The wire support member 60 is arranged perpen-dicularly to antenna support 26 and fastened at its flattened midpoint 62 by a spot weld. The wire support member 60 will thus depend downwardly from the bottom of metal receptacle 40 with the curved bases 70, 72 entirely beneath the floor member 50 and spaced inwardly from side wall member 48 toward the upraised portion 42, preferably about midway between the side wall member 48 and upraised portion 42. On account of the above-described configuration, upon "flashing" of getter material 46, the vaporized metal wiIl not deposit in region 34 shown in Figures 1 and 4 due to the substantially higher side wall 48 and since region 34 is essentially "shadowed"
against the gletter material vapor by the flow member 50 of receptacle 40. Thus, the inwardly curved base `
` - 12312 ~ 57 portions 70, 72 rest in resistive re~ion 34 spaced from getter metal film 30.
By way of specific example a getter assembly in accordance with the presPnt i~vention was made with a container of 305 stainless stelel having an outer diameter of 0.765 in. The height of the container sides was 0.165 in., the width of the getter channel floor was 0.238 and the height of the upraised center portion was 0.076 in. The wire support was formed of 0.045 in. diameter 305 stainless steel wire and held the floor of the getter eontainer 0.155 in. from the inner surface of the picture tube when installed.
Getter material (25% Ba, 25% Al, 50% Ni) in the amount of i,000 mg. was pressed in the channel of the getter.
Using getters of the above type in accordance with the present invention arc current was reduced in tests to about 60 amperes from about 600 amperes which resulted when getters were used which did not have the combination o~ high side walls and "shadowed" support member.
In some applications, the height 77 of wire support member 60 is reduced so that the bottom of receptacle 40 is closer than usual (0.155 inch) to the funnel portion of the picture tube, e.g., about .. . .
~9t3~7 (0.130 to 0.150 inch), in order to enchance the 'l~hadowing"
efect.
- - 8 - ;
.. ' - , . ~.
.
Claims (2)
1. A getter assembly for a cathode ray tube having a funnel portion with a high resistance coating thereon of the order of 2,000 to 6,000 ohms per square to re-duce arc current magnitude, said getter assembly being directly connected electrically to the electron gun of a cathode ray tube and comprising a cylindrically shaped metal recaptacle having an open top; a side wall member; an upraised bottom portion which with said wall member defines in said receptacle an annular channel having a floor member, the height of said side wall member with respect to said floor member being about
2 times greater than the height of said upraised bottom portion; getter material within said annular channel;
a wire support member depending from the bottom of said receptacle the ends of said wire support being bend inwardly toward each other, first downwardly and then upwardly to form two spaced apart curved bases for contacting the resistance coating on the funnel portion of said cathode ray tube, said curved bases being entirely located beneath said floor member and spaced inwardly from said side wall member toward said upraised portion and being located about 0.130 to 0.155 inch from said floor member whereby short circuiting of the resistive coating due to flashing of the getter is avoided.
a wire support member depending from the bottom of said receptacle the ends of said wire support being bend inwardly toward each other, first downwardly and then upwardly to form two spaced apart curved bases for contacting the resistance coating on the funnel portion of said cathode ray tube, said curved bases being entirely located beneath said floor member and spaced inwardly from said side wall member toward said upraised portion and being located about 0.130 to 0.155 inch from said floor member whereby short circuiting of the resistive coating due to flashing of the getter is avoided.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96735578A | 1978-12-07 | 1978-12-07 | |
| US967,355 | 1978-12-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1149857A true CA1149857A (en) | 1983-07-12 |
Family
ID=25512679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000341366A Expired CA1149857A (en) | 1978-12-07 | 1979-12-06 | Getter construction for reducing the arc discharge current in color tubes |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0012359B1 (en) |
| JP (1) | JPS5832896B2 (en) |
| CA (1) | CA1149857A (en) |
| DE (1) | DE2962594D1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1154568B (en) * | 1982-11-11 | 1987-01-21 | Getters Spa | TOGETHER GETTER WITH PERFECTED SUPPORT |
| IT1153657B (en) * | 1982-11-23 | 1987-01-14 | Getters Spa | Getter for CRTs with support mechanism having integral portions |
| JPS61270494A (en) * | 1985-05-22 | 1986-11-29 | 株式会社ニチベイ | Slat for blind and its production |
| KR101134001B1 (en) * | 2008-12-31 | 2012-04-05 | 제일모직주식회사 | Tuyere-type Distributor for Fluidized Bed Reactor for Minimizing Dead Zone |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3547255A (en) * | 1969-03-24 | 1970-12-15 | Gen Electric | Getter assembly |
| US3829730A (en) * | 1973-06-12 | 1974-08-13 | Union Carbide Corp | Getter assembly |
| IT1006453B (en) * | 1974-04-16 | 1976-09-30 | Getters Spa | IMPROVED GETTER DEVICE |
| IT1060443B (en) * | 1976-05-12 | 1982-08-20 | Getters Spa | GETTER DEVICE WITH PERFECTED SUPPORT ELEMENT |
| JPS54159164A (en) * | 1978-06-07 | 1979-12-15 | Hitachi Ltd | Cathode ray tube |
-
1979
- 1979-12-05 EP EP19790104948 patent/EP0012359B1/en not_active Expired
- 1979-12-05 DE DE7979104948T patent/DE2962594D1/en not_active Expired
- 1979-12-06 JP JP54157512A patent/JPS5832896B2/en not_active Expired
- 1979-12-06 CA CA000341366A patent/CA1149857A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0012359B1 (en) | 1982-04-21 |
| EP0012359A1 (en) | 1980-06-25 |
| JPS5580250A (en) | 1980-06-17 |
| DE2962594D1 (en) | 1982-06-03 |
| JPS5832896B2 (en) | 1983-07-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |