CN1739180A - Evaporable getter device for projection tubes - Google Patents

Evaporable getter device for projection tubes Download PDF

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Publication number
CN1739180A
CN1739180A CN 200480002491 CN200480002491A CN1739180A CN 1739180 A CN1739180 A CN 1739180A CN 200480002491 CN200480002491 CN 200480002491 CN 200480002491 A CN200480002491 A CN 200480002491A CN 1739180 A CN1739180 A CN 1739180A
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China
Prior art keywords
wall
barium
radius
angle
inwall
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Pending
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CN 200480002491
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Chinese (zh)
Inventor
丹尼尔·马尔特利
柯拉多·卡莱迪
吉尔乔·朗格尼
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SAES Getters SpA
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SAES Getters SpA
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Publication of CN1739180A publication Critical patent/CN1739180A/en
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    • 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

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  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)

Abstract

There is disclosed an evaporable getter device particularly suitable for being used in tubes for the projection of images on wide screen; the device (10), being ring-shaped, comprises a container (11) of powders (12) of barium or calcium compounds, formed of a bottom wall (22) connected to an external wall (20) and an internal wall (21), both sloping or curved towards the outside in their upper portion, to obtain a distribution of barium or calcium vapours compatible with the application.

Description

The transpirable getter device that is used for projection tube
Technical field
The present invention relates to a kind of transpirable getter device that is used for projection tube.
Background technology
Projection tube belongs to cathode-ray tubing (being commonly referred to as CRT in the art), be used for reproduced image on large-sized screen (generally greater than 50 inches), be used for so-called " home theater " of family, and be used for the public's or private projection, for example show in the session.The image that reproduces can be a black and white, but more generally colored.Under latter event, use three picture tubes, each picture tube can be with one of three primary colors projected image, and synthetic image is last coloured image.Projection tube generally is abbreviated as PRT.
The geometry of projection tube and operating principle and the picture tube similar (being referred to below as " direct-view " type) that is used for traditional television set.Fig. 4 represents the cross section of CRT picture tube with schematic diagram.CRT comprises glass tube T sealing and vacuum, has the anterior S and the rear portion N that form screen, and they are connected by the part F of taper shape or pyramid.In regional N, have electron gun G, fix (only showing one among the figure) by suitable centralizer C.The electron beam that is produced by electron gun is focused and by directly by " yoke ", promptly be arranged on the magnetic deflector of the outside of picture tube, it is positioned at forward slightly position (the roughly zone that connects) with respect to electron gun between part N and F, each point of feasible in this way scanning screen.On screen, have the deposit of the material that is called as fluorophor, it sends the energy that is absorbed once more with the form of visible light by the Electron Excitation of incident the time, thereby produces image.The surface, inside of the part F of picture tube and S forms equipotential by deposition skim graphite and/or aluminium, to avoid producing the electric field of the localization that can cause the electron beam deflecting.In the operating period of picture tube, between this equipotential zone and electron gun zone, has the potential difference of several ten thousand voltage magnitudes, therefore, for fear of short circuit, between these two zones, insert one deck insulating material R, centralizer C contacts with described insulating material.
In all these picture tubes (PRT and direct-viewing kinescope), importantly keep the vacuum (about 10 of the inner space of picture tube for height -4-10 -5The pressure of handkerchief), to avoid causing owing to the collision with gas molecule the diffusion of electron beam, the diffusion of electron beam will make and can not form clearly image on screen.In addition, the oxidant local pressure must be maintained at about 10 -7Below the handkerchief, to avoid the pollution of negative electrode.
As everyone knows, in order to keep vacuum, on the part on the surface, inside of picture tube, generally form the thin deposit of reactive metal, by means of with chemical method it being fixed, it almost can interact with any gas (except rare gas and hydrocarbon).As reactive metal, can use calcium and barium, but in the following description, will mainly describe with reference to barium, it is a most general a kind of metal.When picture tube had been evacuated and has sealed, the compound by by barium was generally BaAl 4, evaporate and the deposit of formation barium.For this purpose, the so-called transpirable getter device of known use, it generally is made of the canister that opens wide, and wherein has the compressing powder of the compound of barium, the perhaps co-catalyst of the powder of described compound and barium evaporation is generally the compressed mixture of the powder of nickel.Be deposited on for fear of barium on the unwanted zone of picture tube inside, also knownly make definite shape, perhaps, make along best direction guide wire steam to the additional suitable deflector of described container by wall canister.Transpirable getter device with the wall of suitable shape or deflector can be known from several patents, comprising US 2,869, and 014,2,907,451,3,195,716,3,996,488 and 6,071,080, also have Korean Patent 314,997.
But the evaporation of the barium in CRT can cause some problems.
First problem is so-called " arc current ".On layer R even deposit a spot of barium can jeopardize its electrical insulation capability, thereby in system even cause strong discharge, discharge stream may be destroyed the electronic control component of electron gun through the centralizer of electron gun (C).
Second problem is owing to the barium on the grid that is deposited on electron gun causes parasitic emission (being called " spurious emissions " in this area).The interior potential difference in this zone that acts on picture tube may cause the extraction of electronics by the sedimental electric field action of barium.D/d then electronics is accelerated towards screen, but because they not by cathode emission, and with irregular mode by yoke deflection, and not as the part of collimated electron beam, thereby on screen, produce pseudo-luminescence phenomenon.
Under the situation of direct-viewing kinescope, the incidence of these phenomenons is comparatively limited, and solves easily.In these picture tubes, by directly visual, therefore arriving electron beam on it, to have an energy that is enough to the activating fluorescent body just enough on screen for image.Because this basic demand, the potential difference between electron gun and screen is general big to be less than about 25kV.In addition, the sedimental thin layer of possible barium can not damage picture quality on screen area.Barium also allows transpirable getter device is arranged on the middle part in F zone attached to the possibility on the screen, and mainly is drawn towards F and S zone (" antenna " position), thus attached on the R layer and the possibility on the grid of electron gun reduce to minimum.
In contrast, under the situation of PRT, image must be projected onto the distance of the outside of picture tube even several meters, in order to keep image focusing on this distance, strikes the energy that the electron beam on the screen has and must be higher than energy required under the direct vision screens.The result of effect is that the potential difference between S zone and electron gun is higher in this case, is the order of magnitude of 30kV, thereby in this case, need reduce to minimum to the deposit of the barium on screen.These requirements force and transpirable getter device are set as far as possible away from screen.In fact, described device generally is set up near electron gun, and general and electron gun is concentric, and before it.But this structure is because arc current and spurious emissions problem but imperfect, in this case, and owing to higher potential difference becomes more imperfect.
In addition, because PRT generally has the size more less than direct-viewing kinescope, it is less to can be used for the sedimental space of barium, but under any circumstance, must provide suitable deposition surface, to guarantee to use the speed and the ability of required gas absorption.
Thereby the transpirable getter device that is used for PRT has stricter and requirement that part is opposite than the getter device that is used for direct vision screens, because it must guarantee (than direct-viewing kinescope require stricter) barium can not be deposited on the unwanted zone, and must guarantee that metal exists with the sedimental form of abundant diffusion.The known getter device for the direct vision screens development can not satisfy these requirements, it causes the too deposit of localization, therefore adsorption rate and adsorption capacity have been reduced (as at US 2,869,014 and 2, under 907,451 the situation), perhaps because they are insecure (under the situation at the device of other above-mentioned patent) aspect regional avoiding barium to be deposited on unwanted.
Summary of the invention
The object of the present invention is to provide a kind of transpirable getter device, it can address the above problem, and especially guarantees to reduce arc current phenomenon and spurious emissions, and guarantees to be applicable to the gas absorption speed and the adsorption capacity of projection tube simultaneously.
According to this purpose of the present invention is to utilize the transpirable getter device that limits in claim 1 and the dependent claims thereof to realize.
Description of drawings
The present invention is described with reference to the accompanying drawings, wherein:
Fig. 1 perspective representation device of the present invention;
Fig. 2 represents device of the present invention with partial sectional view;
Fig. 3 represents the details of device of the present invention to show some characteristic sizes and geometric angle thereof with cutaway view; And
Fig. 4 schematically represents the sectional view of general CRT picture tube.
Embodiment
Referring to Fig. 1, it represents device 10 of the present invention, is made of annular (being that its top view is anchor ring shape) container 11, and it generally is made of metal, and portion has powder packets 12 within it, wherein comprises the material that can discharge barium or calcium at least.
This device can satisfy above-mentioned requirement, and this is because it has specific geometric properties, is shown specifically as Fig. 2 and Fig. 3.The container of device is limited by the outer wall 20 that is connected with each other, inwall 21 and diapire 22, and two walls 20 and 21 are by two bottoms 23 of the axis X-X ' that is parallel to device and 24 and bandy two tops 25 and 26 formations, and part 23 and 24 has radius R respectively 1And R 2Thereby the bottom that wherein has the container of powder packets 12 has the cross section of substantial rectangular.
In order to realize purpose of the present invention, part 25 and 26 size and orientation are most important.Part 25 is the part of a frustum basically, and it is outwardly-bent in this way, make in the plane of the diameter that installs, described part and part 23 form angle α, they are between 20 ° and 50 °, be preferably about 45 °, part 25 stretches out in this way, makes at its outermost point 27 its radius R e at R 1And 1.1R 1Between.When seeing in sectional view, part 26 can be by the arcuate section part of frustum (thereby obtain being essentially) or curve limit.This part is outwardly-bent in this way, makes on the diametral plane of device, and the tangent line of the outer edge of described part and wall 24 form angle β, and it preferably between 20 ° and 40 °, more preferably is approximately 30 ° between 5 ° and 50 °.Part 26 stretches out in this way, makes at its outermost point 28 its radius Rs iAt R 2And R 1Between, and preferably satisfy following relation:
R 2+(R 1-R 2)/2≥R i＞R 2
At last, be for realizing the required last condition of purpose of the present invention, in the cross section of device 10 diametral plane, between point 27 and 28 apart from d 1At least equal difference R i-R 20.8 times.This last condition can obtain with different modes by the length of part 25,26 and angle α are carried out computing with β.In another embodiment, in order to obtain this condition, can carry out computing to the height of bottom 23 and 24 and obtain.Specifically, the height of establishing part 23 and 24 respectively is h 1, h 2, can realize in this way, make h 2〉=1.5h 1
Container 11 generally is formed from steel, particularly AISI 304 or AISI 305, its thickness about 0.10 and 0.20mm between.
As described in preface part, utilize device of the present invention, can evaporate both barium and calcium.Compound, mixture and the condition that is used for evaporate both barium is that this area is known, for example can be by described patent or by US 4,642, and 516,4,961,040,6,104,138 and 6,306,314 learn.
As pioneer's compound, can use Compound C aAl about the use calcium that just proposes in recent years 2, this is US 6,583, and the theme of 559 B1 perhaps uses the Ca-Ba-Al ternary alloy three-partalloy of rich calcium, and this is the theme of disclosed PCT application WO 03/038139.These compounds have the evaporation characteristic different with the compound of barium, are used for therefrom evaporation of calcium, can use the two-stage process that discloses at disclosed PCT application WO 03/043047.Under the situation of the device that is used for evaporation of calcium, the co-catalyst as evaporation preferably uses titanium.
At last, can so that improve sedimental porousness (it mainly increases the speed of gas absorption), for example the compound of nitrogenize be added in the powder packets, for example Fe structure applications known in the art in device of the present invention 4N, percentage by weight the powder total weight about 2% and 4% between.
The geometry of device of the present invention and similar with reference among the described US 2,907,451 of Fig. 1.But this existing patent only shows a kind of general shape of device, does not provide CONSTRUCTED SPECIFICATION.The difference of device of the present invention and prior art is that at first the projection of part 26 " drops on " on the powder packets 12, and by d 1The bigger size of the delivery channel that is used for metal vapors that limits.The one type of prior art syringe that is designed to direct vision screens can not satisfy all requirements of PRT, and particularly it can not provide the sufficient diffusion of barium, makes to guarantee high GAS ABSORPTION performance.

Claims (10)

1. a transpirable getter device (10), metal ring container by upward opening constitutes, wherein has powder packets (12), described powder packets comprises the material that can discharge barium or calcium at least, described container is made of the outer wall that is connected with each other (20), inwall (21) and diapire (22), described outer wall comprises parallel bottom (23) and bandy top (25) of axis (X-X ') with device, described inwall comprises the bottom (24) parallel with the axis (X-X ') of device and to the top (26) of the outer bend of device, it is characterized in that:
The bottom (23) of-described outer wall (20) has radius R 1
The bottom (24) of-described inwall (21) has radius R 2＜R 1
The top (25) of-described outer wall (20) and the described bottom (23) of same wall are formed on the angle α between 20 ° and 50 °, and the radius R e that its length makes in outermost point (27) satisfies relation: 1.1R 1〉=Re＞R 1
The top (26) of-described inwall (21) is outwardly-bent in this way, makes the bottom (24) of the tangent line of outer edge on described top and same wall be formed on the angle β between 5 ° and 50 °, and its length makes its radius R in outermost point (28) iSatisfy relation: R 1〉=R i＞R 2And
-measure between the described outermost point on described top on the diametral plane of described device apart from d 1Satisfy d 1〉=0.8 (R 1-R 2).
2. device as claimed in claim 1, wherein said angle α approximately is 45 °.
3. device as claimed in claim 1, wherein said angle β is between about 20 ° and 45 °.
4. device as claimed in claim 3, wherein said angle β is approximately 30 °.
5. device as claimed in claim 1, wherein said radius R iMake to satisfy and concern R 2+ (R 1-R 2)/2 〉=R i＞R 2
6. device as claimed in claim 1, the height h of the bottom of wherein said inwall 2At least equal the height h of the bottom of outer wall 11.5 times.
7. device as claimed in claim 1, wherein said barium releasable material is BaAl 4
8. device as claimed in claim 7, wherein said powder packets also comprises nickel.
9. device as claimed in claim 1, wherein said calcium releasable material is CaAl 2
10. device as claimed in claim 9, wherein said powder packets also comprises titanium.
CN 200480002491 2003-04-07 2004-03-17 Evaporable getter device for projection tubes Pending CN1739180A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI20030679 ITMI20030679A1 (en) 2003-04-07 2003-04-07 EVAPORABLE GETTER DEVICE FOR PROJECTION TUBES
ITMI2003A000679 2003-04-07

Publications (1)

Publication Number Publication Date
CN1739180A true CN1739180A (en) 2006-02-22

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN 200480002491 Pending CN1739180A (en) 2003-04-07 2004-03-17 Evaporable getter device for projection tubes

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CN (1) CN1739180A (en)
IT (1) ITMI20030679A1 (en)
WO (1) WO2004090924A2 (en)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1079746B (en) * 1952-09-27 1960-04-14 E S Societa Apparacchi Elettri Getter container
US3719433A (en) * 1970-04-21 1973-03-06 Getters Spa Getter device
IT1019731B (en) * 1974-07-19 1977-11-30 Getters Spa GETTER DEVICE EQUIPPED WITH A PERFECTED DEFLECTOR
US5841228A (en) * 1996-06-19 1998-11-24 U.S. Philips Corporation Getter assembly with stiffened getter wand and CRT
KR19990044059A (en) * 1996-06-24 1999-06-25 요트.게.아. 롤페즈 Vacuum device

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WO2004090924A3 (en) 2005-04-28
ITMI20030679A1 (en) 2004-10-08
WO2004090924A2 (en) 2004-10-21

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