US3558962A - High yield getter device - Google Patents
High yield getter device Download PDFInfo
- Publication number
- US3558962A US3558962A US783029A US3558962DA US3558962A US 3558962 A US3558962 A US 3558962A US 783029 A US783029 A US 783029A US 3558962D A US3558962D A US 3558962DA US 3558962 A US3558962 A US 3558962A
- Authority
- US
- United States
- Prior art keywords
- getter
- container
- tube
- getter material
- sidewall
- 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 - Lifetime
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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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
- H01J7/14—Means for obtaining or maintaining the desired pressure within the vessel
- H01J7/18—Means for absorbing or adsorbing gas, e.g. by gettering
- H01J7/186—Getter supports
Definitions
- a getter device capable of providing large amounts of active getter material comprising a pan-shaped container for holding pressed getter material and an auxiliary heating means at least partially buried in said pressed getter material.
- a commonly used getter construction consists of a container, such as an annular U-shpaed receptacle, with the getter material pressed into the container. This assembly is mounted in an electron tube, for example, a television picture tube. After the tube is evacuated, the residual gases left in the tube are removed by heating the getter container and material therein to a high temperature, suitably by induction heating, whereupon the getter material is flashed or vaporized. The vaporized getter material adsorbs or reacts with the residual gases and removes them as low vapor pressure solid condensates and continues to adsorb any further liberated gases throughout the life of the tube.
- the getter material comprises a mixture or alloy of metals such as, for example, barium and aluminum. It is the barium component of this mixture which comprises the reactive material.
- color tubes having three electron guns and a metal shadow mask have been considered in the past to require a yield of l25to 175 mg. of barium.
- the barium-aluminum powder mixture might have contained up to about 50 percent aluminum, the total amount of gettering powder mixture in the container before flashing could be from 250 to 350 mg. It has also been found desirable to employ exothermic gettering powders in color television picture tubes.
- An exothermic gettering powder can comprise a barium-aluminum alloy or mixture plus about an equal weight of powdered nickel.
- the nickel reacts exothermically with the aluminum upon heating to supply additional heat for evaporating the barium as well as to assist in forming a solid residue of the unflashed material which remains in the container.
- a typical channel ring exothermic getter used in color television tubes may contain, for example, 500 mg. of a 25 percent barium25 percent aluminum-50 percent nickel exothermic alloy yielding about 125 mgs. of barium when fully flashed.
- the getter container itself may comprise a U-shaped channel formed into a ring of about 25 mm. outside diameter and having a channel width of about 0.1 inch.
- getter containers of the above dimensions can be filled with an increased amount of barium-aluminum-nickel alloy, say 600 mgs. instead of 500 mg., and a barium yield of about 150 mg. will be obtained.
- An electron tube particularly a television picture tube, generally comprises a neck portion in which are located the electron gun or guns and auxiliary equipment; an enlarged bulb portion which terminates in a generally flat viewing screen; and a funnel portion joining the neck and bulb portions.
- the getter container is often mounted in the funnel portion of the tube. This is accomplished by mounting the getter container at the end of a springlike metallic strip support arm or antenna, the other end of which is fixed to a wall of the electron gun in the neck portion of the tube. The spring is biased to force the getter container against the wall of the tube in the funnel portion, out of the path of the electron beams.
- An RF induction heating unit comprising a coil spirally wound in a conical shape which approximates the curve of the tube wall in the funnel area is positioned near this wall of the glass tube opposite the getter container. After the tube is partially evacuated by vacuum pumping and sealed, the coil is energized causing an induced current to flow in the getter container, heating the container and flashing the getter material.
- a high yield getter for mounting in an electron tube against an inner wall thereof and containing getter material to be flashed by induction heating of said getter by circular RF field produced by an induction coil positioned externally of said tube wall and opposite said mounted getter, said getter comprising a metallic pan-shaped container having a vertical sidewall formed around the perimeter of a floor member with getter material pressed into the space formed by said sidewall and floor member, and an auxiliary heating means at least partially buried in said pressed getter material for conducting heat into the mass of said pressed getter material.
- the auxiliary heating means comprises a perforated metallic member overlying the container floor member and being buried in the mass of pressed getter material intermediate the top and bottom surfaces thereof, with getter material present in the perforations of said metallic member.
- the high capacity getter may comprise a pan-shaped container having a vertical sidewall formed around a flat circular floor member, a discshaped piece of metallic screen lying in the space formed by the sidewall and floor member, said screen joined to the underlying floor member at one or more points, and getter material pressed into said space at least partially burying said screen.
- FIG. 1 is a schematic view of the neck and funnel portions of a television picture tube, in cross section, including the getter device of this invention mounted in the antenna" position and showing the positioning of the heating coil;
- FIG. 2 is a plan view of a high yield getter container of this invention showing the disc-shaped screen in place on the floor member but prior to filling of the container with getter material;
- FIG. 3 is an end view of the getter container of FIG. 2;
- FIG. 4 is a sectional view along the line 4-4 of FIG. 1, but showing getter material pressed into the container.
- FIG. 1 there is shown a portion of a typical glass television picture tube.
- a typical glass television picture tube Such a tube may be viewed as having three main parts: a neck portion 11; a funnel portion 12; and the bulb or a main tube, only a portion 13 of which is shown.
- the central axis 6 of the tube extends through these parts.
- the division of a tube into such parts is arbitrary and it is not meant here that the getter of this invention can only be'used in a funnel portion of a tube. Under suitable circumstances, the getter of this invention could be mounted nearer to the gun in the neck of the tube or further into the bulb of the tube as desired.
- the getter of this invention can be used in other typed of electron tubes than the television picture tube described herein and can also be used in other types of evacuated vessels.
- an electron gun 14 (or guns in the case of a color tube) is shown positioned in the neck of the tube.
- An antenna spring or support arm 15 is shown fixed at one end 16 to the sidewall of the gun and having mounted on its opposite end 17 the getter container 18.
- the support arm 15 is a piece of thin, flexible, flat metal strip, such as for example stainless steel or a nickel-base alloy, biased to urge the getter container 18 against the wall 19 of the tube and out of the path of the electron beam.
- the getter container is supported in a position out of direct contact with the glass wall of the tube by a support member such as 20, otherwise the glass wall might crack if it were contacted directly by the hot getter container.
- An RF induction heating coil 21 is shown positioned near the outer wall of the funnel portion of the tube.
- the coil and getter container must be arranged symmetrically so that the heating currents induced in the getter containers are uniform and symmetrical.
- the RF field generated by this coil can be viewed as comprising elliptical .flux lines, the long sides of which loop through the open central core of the coil, being more concentrated at the inner periphery of the individual windings of the coil and increasingly less dense nearer the center axis of the coil.
- the flux lines then flow around the outside of the coil.
- the arrow 22 represents the central axis of the coil as well as the getter container. Portions of the elliptical flux lines are represented schematically by the lines 23.
- the flux lines in the vicinity of the getter container are most concentrated at the periphery of the circular container, as represented by the lines 23.
- the heating currents induced in the getter container are therefore most concentrated in circular patterns near the periphery of the container where these outer portions of the getter container intercept the flux lines.
- the central portion of the getter container is thus not heated as effectively as the outer portion with the result that there would be incomplete flashing of the getter material in this central portion of the container in the short time allowed for heating the container.
- the getter container 24 has a continuous vertical sidewall 25 formed around a circular floor member 26 forming a pan-shaped receptacle into which getter material may be pressed.
- a metallic screen 27 cut into the shape of a disc of a diameter slightly less than the diameter of the pan is placed in the container and joined thereto, as by several spot welds, for example at the center of container 28 and at several other points 29.
- the getter material 30 can then be pressed into the container so as to cover the screen 27 and fill the various openings in and under the screen, as shown in FIG. 4.
- a mounting bar 31 extends across the underside of the container and is welded to the floor member, for example at points 32 and 33.
- a wire support member 20 may be welded at its midpoint 34 to the underside of the mounting bar 31.
- the antenna support arm 15 is connected at its'end I7 to the projecting tab 35 on the mounting bar and the getter container mounted in the tube with the wire support member 20 resting on the tube wall.
- the screen 27 serves as an auxiliary heating means during the getter flashing operation as follows: when the induction coil is energized and the getter container heated, the portions of the screen which are at the periphery of the getter con tainer, i.e., near the sidewall 25, take heat from this outer annular portion of the container and conduct it radially inward into the mass of getter material near the center 28 of the container. As a result, this central mass of getter material receives more heat than if there were no screen present. While the container floor member 26 also conducts heat from its outer portions in towards its center, this member only contacts the bottom surface of the packed mass of getter material.
- the getter material in the center of the container is thus more effectively heated to a flashing temperature and the barium vapor is discharged in a substantially uniform pattern over most areas of the container.
- the screen 27 is a metallic mesh of interwoven metal wires.
- Other types of perforated members may be used as the auxiliary heating means. They need only be metallic to conduct the heat to the central mass of gettermaterial, and should have perforations so as to allow getter material to be in close contact with this heating member and so that the member does not occupy too much of the space in the container which is primarily intended to hold getter material.
- the auxiliary heating member should extend from the peripheral areas of the getter container near the sidewall to the center of the container. In this way, the auxiliary heating member can take heat from the peripheral areas where the RF flux is densest and where the heating effect is greatest, and transmit such heat to the central mass of the getter container where the flux density is least and where the induction heating is lowest.
- getter containers holding large amounts of getter material are provided which yield reactive barium getter material in the same manner and with substantially the same efficiency as the more typicalchannel ring getter containers, despite the negative effects of the circular heating pattern available for flashing getters in television picture tubes. Since the pan-shape getter can hold considerably more getter material in a container no larger than the channel ring getter, an advance in the art is provided whereby additional gettering power is made available for electron tubes without necessitating any costly changes in tube design or getter flashing technique.
- the screen serves to hold the pressed getter material together as a coherent mass, particularly during and after flashing.
- the screen acts as a reinforcing means and holds the getter residue in the container after flashing, preventing the ejection of any solid particles into the tube interior where such foreign bodies might interfere with operation of the electronic system. This is so even in those cases where the screen is not actually welded to the floor of the container.
- the getter material may be partially pressed into an empty getter container, and then a disc-shaped screen placed over the powder and pressed thereinto.
- the screen despite its lack of direct contact with the outer portions of the floor member will still become highly heated at its outer portions and will conduct heat into the central mass of getter material. Furthermore the screen, while only pressed into the surface of the powder and not directly anchored to the container, will fuse into the powder on heating and will bind the residue together preventing ejection of particles.
- the auxiliary heating member should generally be of a metal which will not melt as a result of the getter heating operation and additionally should be nonmagnetic.
- Stainless steel mesh for example SS304, is a suitable material.
- the stainless steel member containing nickel and iron, also tends to react exotherrnically at its surfaces with the getter material in the container and therefore aids in directly supplying some of the heat needed to flash the barium. All other portions of the getter containers should be nonmagnetic metals, e.g., stainless steels and other nonmagnetic alloys.
- An example of a getter of this invention is a pan-shaped getter container of the type shown in FIGS. 2 through 4 having an outside diameter of about 25 mm.
- the height of the vertical sidewall is about 0.085 inches.
- a stainless steel screen of X 10 mesh, i.e., 10 wires per inch, is cut to a diameter slightly less than the inner diameter of the container and inserted therein and spot welded at five points.
- About 2,000 mg: of barium-aluminum-nickel powder is pressed under high pressure into the screen containing getter receptacle. This powder nominally comprises 25 percent each of barium and aluminum in the form of an alloy, and 50 percent powdered nickel.
- the barium-aluminum-nickel contents may be varied from these proportions as desired.
- a getter of this type is mounted in a tube, as shown in FlG. 1, and flashed, a yield of barium in excess of 400 mg. may be obtained. Yields of 80 to 85 percent of the barium contained in the getter may be obtained using the arrangement of this invention.
- a high yield getter for mounting in the funnel portion of an electron picture tube against a wall thereof for discharging large quantities of active getter material into the tube interior when the getter is heated by currents induced from an RF field created by a coil positioned outside the tube opposite the getter, said getter comprising a pan-shaped container having a vertical sidewall formed around the perimeter of a floor member, a disc-shaped piece of metallic screen lying in the space formed by the sidewall an joined to the floor member with powdered getter material pressed into the space formed by said sidewall and floor member at least partially burying said screen, whereby when the coil is activated the metallic screen serves to conduct heat from the peripheral portions of the container adjacent said sidewall where the induced heating current is most intense into the central mass of the pressed getter materiaLwhere the induced heating current is less intense to provide for uniform flashing of the active contents of the getter material and whereby said metallic screen serves to hold the getter material residue in said container after flashing.
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- Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
Abstract
Description
Claims (1)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US78302968A | 1968-12-11 | 1968-12-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3558962A true US3558962A (en) | 1971-01-26 |
Family
ID=25127961
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US783029A Expired - Lifetime US3558962A (en) | 1968-12-11 | 1968-12-11 | High yield getter device |
Country Status (1)
Country | Link |
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US (1) | US3558962A (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2479557A1 (en) * | 1980-03-26 | 1981-10-02 | Rca Corp | PROCESS FOR VAPORIZING MATERIALS ABSORBING THE LAST TRACES OF GAS IN A SUCCESSION OF CATHODE RAY TUBES |
US4302063A (en) * | 1980-02-28 | 1981-11-24 | Rca Corporation | Method for vaporizing getter material in a vacuum electron tube |
US4323818A (en) * | 1978-12-07 | 1982-04-06 | Union Carbide Corporation | Getter construction for reducing the arc discharge current in color TV tubes |
US4409174A (en) * | 1981-12-24 | 1983-10-11 | The United States Of America As Represented By The Secretary Of The Army | Method for batch production of isostatically pressed calcium powder discs |
US4445872A (en) * | 1982-01-18 | 1984-05-01 | Rca Corporation | Method of detecting the vaporization of getter material during manufacture of a CRT |
US4961040A (en) * | 1988-04-20 | 1990-10-02 | Saes Getters Spa | High yield pan-shaped getter device |
EP0853328A1 (en) * | 1997-01-10 | 1998-07-15 | SAES GETTERS S.p.A. | Frittable evaporable getter device having a high yield of barium |
WO2000028568A1 (en) * | 1998-11-10 | 2000-05-18 | Saes Getters S.P.A. | Evaporable getter device with reduced loss of particles and process for producing the same |
US6104138A (en) * | 1997-01-10 | 2000-08-15 | Saes Getters S.P.A. | Frittable-evaporable getters having discontinuous metallic members, radial recesses and indentations |
US6583559B1 (en) | 1999-06-24 | 2003-06-24 | Saes Getter S.P.A. | Getter device employing calcium evaporation |
US6793461B2 (en) | 2001-10-29 | 2004-09-21 | Saes Getters S.P.A. | Device and method for producing a calcium-rich getter thin film |
US6851997B2 (en) | 2001-11-14 | 2005-02-08 | Saes Getters S.P.A. | Process for depositing calcium getter thin films inside systems operating under vacuum |
WO2008033560A3 (en) * | 2006-09-15 | 2008-07-24 | Getters Spa | Metal getter systems |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2060861A (en) * | 1934-09-29 | 1936-11-17 | Rca Corp | Getter assembly |
US3390758A (en) * | 1967-03-21 | 1968-07-02 | Union Carbide Corp | Getter assembly |
US3422299A (en) * | 1964-07-09 | 1969-01-14 | Westinghouse Electric Corp | Fluorescent lamp having an integral mercury-vapor pressure control assembly with amalgam-forming metal and amalgam stabilizing means |
-
1968
- 1968-12-11 US US783029A patent/US3558962A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2060861A (en) * | 1934-09-29 | 1936-11-17 | Rca Corp | Getter assembly |
US3422299A (en) * | 1964-07-09 | 1969-01-14 | Westinghouse Electric Corp | Fluorescent lamp having an integral mercury-vapor pressure control assembly with amalgam-forming metal and amalgam stabilizing means |
US3390758A (en) * | 1967-03-21 | 1968-07-02 | Union Carbide Corp | Getter assembly |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4323818A (en) * | 1978-12-07 | 1982-04-06 | Union Carbide Corporation | Getter construction for reducing the arc discharge current in color TV tubes |
US4302063A (en) * | 1980-02-28 | 1981-11-24 | Rca Corporation | Method for vaporizing getter material in a vacuum electron tube |
FR2479557A1 (en) * | 1980-03-26 | 1981-10-02 | Rca Corp | PROCESS FOR VAPORIZING MATERIALS ABSORBING THE LAST TRACES OF GAS IN A SUCCESSION OF CATHODE RAY TUBES |
DE3112001A1 (en) * | 1980-03-26 | 1982-02-18 | RCA Corp., 10020 New York, N.Y. | "METHOD FOR EVAPORATING GETTER MATERIAL IN A SEQUENCE OF CATHODE RAY TUBES" |
US4335926A (en) * | 1980-03-26 | 1982-06-22 | Rca Corporation | Method for vaporizing getter material in a succession of cathode-ray tubes |
US4409174A (en) * | 1981-12-24 | 1983-10-11 | The United States Of America As Represented By The Secretary Of The Army | Method for batch production of isostatically pressed calcium powder discs |
US4445872A (en) * | 1982-01-18 | 1984-05-01 | Rca Corporation | Method of detecting the vaporization of getter material during manufacture of a CRT |
US4961040A (en) * | 1988-04-20 | 1990-10-02 | Saes Getters Spa | High yield pan-shaped getter device |
EP0853328A1 (en) * | 1997-01-10 | 1998-07-15 | SAES GETTERS S.p.A. | Frittable evaporable getter device having a high yield of barium |
US6104138A (en) * | 1997-01-10 | 2000-08-15 | Saes Getters S.P.A. | Frittable-evaporable getters having discontinuous metallic members, radial recesses and indentations |
CN1113376C (en) * | 1997-01-10 | 2003-07-02 | 工程吸气公司 | Frittable evaporable getter device having high yield of barium |
WO2000028568A1 (en) * | 1998-11-10 | 2000-05-18 | Saes Getters S.P.A. | Evaporable getter device with reduced loss of particles and process for producing the same |
US6583559B1 (en) | 1999-06-24 | 2003-06-24 | Saes Getter S.P.A. | Getter device employing calcium evaporation |
US6793461B2 (en) | 2001-10-29 | 2004-09-21 | Saes Getters S.P.A. | Device and method for producing a calcium-rich getter thin film |
US20040195968A1 (en) * | 2001-10-29 | 2004-10-07 | Saes Getters S.P.A. | Composition used in producing calcium-rich getter thin film |
US20050163930A1 (en) * | 2001-10-29 | 2005-07-28 | Saes Getters S.P.A. | Device and method for producing a calcium-rich getter thin film |
US7083825B2 (en) * | 2001-10-29 | 2006-08-01 | Saes Getters S.P.A. | Composition used in producing calcium-rich getter thin film |
US6851997B2 (en) | 2001-11-14 | 2005-02-08 | Saes Getters S.P.A. | Process for depositing calcium getter thin films inside systems operating under vacuum |
WO2008033560A3 (en) * | 2006-09-15 | 2008-07-24 | Getters Spa | Metal getter systems |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: MORGAN GUARANTY TRUST COMPANY OF NEW YORK, AND MOR Free format text: MORTGAGE;ASSIGNORS:UNION CARBIDE CORPORATION, A CORP.,;STP CORPORATION, A CORP. OF DE.,;UNION CARBIDE AGRICULTURAL PRODUCTS CO., INC., A CORP. OF PA.,;AND OTHERS;REEL/FRAME:004547/0001 Effective date: 19860106 |
|
AS | Assignment |
Owner name: UNION CARBIDE CORPORATION, Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:MORGAN BANK (DELAWARE) AS COLLATERAL AGENT;REEL/FRAME:004665/0131 Effective date: 19860925 |
|
AS | Assignment |
Owner name: GETTERS CORPORATION OF AMERICA, A CORP. OF DE. Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:UNION CARBIDE CORPORATION;REEL/FRAME:004817/0868 Effective date: 19870901 |
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AS | Assignment |
Owner name: SAES GETTERS SPA, ITALY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GETTERS CORPORATION OF AMERICA;REEL/FRAME:005456/0478 Effective date: 19900927 |