EP0044239A1 - Microchannels image intensifier tube and image pick-up assembly comprising such a tube - Google Patents

Microchannels image intensifier tube and image pick-up assembly comprising such a tube Download PDF

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Publication number
EP0044239A1
EP0044239A1 EP81401034A EP81401034A EP0044239A1 EP 0044239 A1 EP0044239 A1 EP 0044239A1 EP 81401034 A EP81401034 A EP 81401034A EP 81401034 A EP81401034 A EP 81401034A EP 0044239 A1 EP0044239 A1 EP 0044239A1
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Prior art keywords
tube
image
image intensifier
electrodes
getter
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Granted
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EP81401034A
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German (de)
French (fr)
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EP0044239B1 (en
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Yves Beauvais
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Thales SA
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Thomson CSF SA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/50—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output
    • H01J31/501—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output with an electrostatic electron optic system
    • 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

Definitions

  • the invention relates to image intensifier tubes comprising a micro-channel element.
  • Such an element consists of a large number of channels of very small diameter juxtaposed, produced in a wafer of a material with high secondary emission coefficient and low electrical conductivity.
  • a voltage of a few hundred volts is applied between the ends of the channels, each electron entering one of them causes the emission of secondary electrons, by impact on the wall of the channel, which electrons in turn generate new secondary electrons and so on, the result being a gain in electrons which can commonly reach values of 10 4 to 10 5 .
  • the object of the invention is to improve this stability and to increase the life of the tube.
  • the electronic optics ensures the acceleration and the transfer of the electrons emitted by each point of the photocathode towards a homologous point of the wafer 4; this electron transfer is accompanied by an image inversion, as shown by the brush drawing of electrons (curved arrows, without mark), corresponding to one of these points.
  • the electronic optical device is made up of several electrodes, the two main ones of which have been shown in the figure, namely the focusing electrode and the correction electrode; these electrodes bear the marks 30 and 31 respectively.
  • the secondary electrons are accelerated and focused towards the different) anointed with the luminescent screen by an electric field established between the wafer 4 and the screen 5; the figure shows, without reference mark, the cone of impact, on the screen, of the electrons of a channel, cone of which we have, for clarity, deliberately exaggerated the angle at the top.
  • These impacts form on the screen a bright image corresponding to the incident image.
  • inlet window and that of the tube outlet window have not been specified in the drawings. We only retained the presence of the photocathode in the first and of the luminescent screen in the second, between which takes place the path of the electrons produced by the photocathode, or photoelectrons, and which are the only elements necessary understanding the invention.
  • These windows may include other elements, such as optical fiber wafers or scintillators in the case of incident radiation outside the visible spectrum, as known in the art.
  • Such a tube makes it possible to obtain on its output screen an image with high luminance, thanks to the energy communicated to electrons by the potentials applied on the one hand, and to the multiplication ensured by the wafer of micro-channels on the other hand This property is used in many devices for the observation of dimly lit scenes, particularly night scenes.
  • FIG. 2 gives one of the most common examples of this distribution of potentials in an intensifier tube such as that described; the marks are used here to designate the average levels of the electrodes of the previous figure.
  • the electrons emitted by the photocathode are first accelerated then slightly slowed down, but reach the entry of the micro-channels with a positive acceleration; on the other hand, the ions created in these micro-channels, and whose potential is at most equal to that of the exit face 42 (for the electrons) of the wafer 4, are slowed down between the opposite face, entry, 40 thereof and the focusing electrode 30; their energy is insufficient for them to reach this electrode, which pushes them back towards the micro-channel wafer, towards the walls of the enclosure 20 and more particularly towards the correction electrode 31, the potential of which is the most negative. They fail to cross the top A of the potential profile.
  • correction electrode 31 the role of the correction electrode 31 is to standardize the angle of incidence of the electron brushes on the wafer of micro-channels, in order to standardize the gain, and to reduce the distortion of the picture.
  • the previous arrangement has the advantage of avoiding the degradation of the photocathode by a part of the ions present in the tube; on the other hand it does not limit the rise in pressure in the tube following the appearance of these ions and which indirectly has the same effects.
  • a getter material is placed on the parts of the tube to which the ions located in the last part of the path followed by the elections preferentially go, in particular on the correction electrode 31 and on the surface of the focalization electrode 30 facing the micro-channel plate 4, of the example described, under the conditions which will be explained.
  • Figure 3 shows, without limitation, an embodiment of the invention; in this figure, the left part, 3 (a) represents a half-section of a micro-channel image intensifier of the known art, and the right part, 3 (b) the other half-section of the same tube modified by the invention.
  • the figure shows three possible modifications, but not necessarily carried out simultaneously in the same tube of the invention.
  • the focusing electrode 30 is modified so as to allow the electrical supply of a getter; it is provided in two parts 301 and 302; the getter 50 is placed between these two parts, advantageously curved so as to serve as masks protecting against evaporation the various constituent parts 21-24 of the insulating envelope 20, as well as the micro-channel plate 4, of one side and photocathode 1 on the other, in the case of an evaporable getter with tantalum, titanium, barium, etc.
  • the same arrangement can be used in the case of a non-evaporable getter, with aluminum zirconium oxide for example; in this case the getter is supplied between the two parts of the electrode to which it serves as an electrical connection, by connections, 51 and 52 in the figure.
  • getter is arranged at the level of the correction electrode 31 also made in two parts 311 and 312 preferably bent for the same reasons; the getter carries the mark 60 in the figures and its connections the marks 61 and 62.
  • the prior art provides in some cases for housing a getter 80 at the photocahode connection, connection which consists, according to widespread practice, in a cup 70 welded to the input window 2; this getter is fed through the queusot 90 through the passage 100.
  • a screen 110 is provided to protect the near photocathode against evaporation of the getter.
  • the invention provides, to pass from such a getter, which is placed at a place in the tube where the formation of ions is unlikely.
  • the tip, or cathode connection is thus simplified and its diameter reduced, all other things being equal, compared to the case of tubes of the prior art. Such a reduction in the radial size of the tubes constitutes an advantage of the invention.
  • the entry window includes, in front of the photocathode, a scintillator attached to it.
  • the invention also covers such assemblies.

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  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)

Abstract

L'invention concerne un tube intensificateur d'image à micro-canaux. Afin de limiter la quantité accrue d'ions prenant naissance dans le tube du fait de la présence d'un élément à micro-canaux (4) dans celui-ci, l'invention prévoit de disposer des getters (50, 60) sur le trajet probable suivi par les ions sous l'action des potentiels appliqués aux électrodes ; ces getters sont fixés aux électrodes (30, 31) faites en deux parties (301, 302 et 311, 312) pour permettre éventuellement l'alimentation des getters, et ces parties recourbées pour servir de masques dans le cas de getters vaporisables. Applications : Prise de vues nocturne et radiologie médicale, notamment.The invention relates to a microchannel image intensifier tube. In order to limit the increased amount of ions originating in the tube due to the presence of a micro-channel element (4) therein, the invention provides for having getters (50, 60) on the probable path followed by the ions under the action of the potentials applied to the electrodes; these getters are fixed to the electrodes (30, 31) made in two parts (301, 302 and 311, 312) to optionally allow feeding of the getters, and these curved parts to serve as masks in the case of vaporizable getters. Applications: Night shots and medical radiology, in particular.

Description

L'invention concerne les tubes intensifi- cateurs d'images comportant un élément à micro-canaux.The invention relates to image intensifier tubes comprising a micro-channel element.

Un tel élément est constitué d'un grand nombre de canaux de très faible diamètre juxtaposés, réalisés dans une galette d'un matériau à coefficient d'émission secondaire élevé et à faible conductibilité électrique. Lorsqu'une tension de quelques centaines de volts est appliquée entre les extrémités des canaux, chaque électron pénétrant dans l'un deux provoque l'émission d'électrons secondaires, par impact sur la paroi du canal, lesquels électrons engendrent à leur tour de nouveaux électrons secondaires et .ainsi de suite, le résultat étant un gain en électrons pouvant atteindre couramment des valeurs de 104 à 105.Such an element consists of a large number of channels of very small diameter juxtaposed, produced in a wafer of a material with high secondary emission coefficient and low electrical conductivity. When a voltage of a few hundred volts is applied between the ends of the channels, each electron entering one of them causes the emission of secondary electrons, by impact on the wall of the channel, which electrons in turn generate new secondary electrons and so on, the result being a gain in electrons which can commonly reach values of 10 4 to 10 5 .

L'un des problèmes soulevés par l'introduction de galettes de micro-canaux dans les tubes intensificateur d'image, et dans les tubes à vide en général, est celui du dégagement important de gaz auquel donne lieu le matériau de la galette, sous l'effet notamment du bombardement électronique. Les gaz libérés sont facilement ionisés par les électrons, les ions ainsi formés se trouvant accélérés vers les parties à bas potentiel du tube, la photocahtode notamment, dans le cas' d'intensificateurs d'images. L'érosion ionique de la photocathode entraine alors sa destruction progressive et abrège,de ce fait,la vie du tube. En outre l'émission d'électrons par la photocathode ne cesse de dé- croître avec le temps, ce qui ôte toute stabilité au fonctionnement du tube.One of the problems raised by the introduction of microchannel wafers in image intensifier tubes, and in vacuum tubes in general, is that of the significant release of gas which gives rise to the material of the wafer, under the effect in particular of electronic bombardment. The released gases are easily ionized by the electrons, the ions thus formed being accelerated towards the low potential parts of the tube, the photocahtode in particular, in the case of image intensifiers. The ionic erosion of the photocathode then causes its gradual destruction and therefore shortens the life of the tube. In addition, the emission of electrons by the photocathode continues to decrease over time, which removes any stability in the operation of the tube.

L'invention a pour objet d'améliorer cette stabilité et d'accroître la durée de vie du tube.The object of the invention is to improve this stability and to increase the life of the tube.

L'invention sera mieux comprise en se reportant à la description qui suit et aux figures jointes qui représentent :

  • - Figure 1 : une vue schématique d'ensemble d'un tube intensificateur d'images à micro-canaux tel que connu de l'art;
  • - Figure 2 : la répartition des potentiels le long de l'axe dans un tube tel que celui représenté sur la figure précédente ;
  • - Figures 3a et 3b : des vues comparées de réalisations d'un intensificateur d'images suivant l'art antérieur 3(a) et suivant l'invention 3(b).
The invention will be better understood by referring to the description which follows and to the attached figures which represent:
  • - Figure 1: a schematic overview of an image intensifier tube with micro-channels as known in the art;
  • - Figure 2: the distribution of potentials along the axis in a tube such as that shown in the previous figure;
  • - Figures 3a and 3b: comparative views of embodiments of an image intensifier according to the prior art 3 (a) and according to the invention 3 (b).

On rappelle tout d'abord la structure générale d'un intensificateur d'images à micro-canaux telle que connue de l'art antérieur. Cette structure est représentée sur la figure 1, dans le cas d'un tube cylindrique d'axe X'X.First of all, we recall the general structure of a micro-channel image intensifier as known from the prior art. This structure is shown in Figure 1, in the case of a cylindrical tube of axis X'X.

Un tel intensificateur comprend :

  • - une couche photo-émissive ou photocathode, 1,incorporée à une fenêtre d'entrée 2; la photocathode reçoit, en fonctionnement, le rayonnement incident,représenté par la flèche ondulée,et émet en chaque point un nombre d'électrons proportionnel au flux incident reçu par ce point ;
  • - un dispositif d'optique électronique 3, électrostatique ou électromagnétique ;
  • - une galette de micro-canaux 4 ;
  • - un écran cathodo-luminescent 5,partie intégrante d'une fenêtre de sortie 6.
Such an intensifier includes:
  • - a photo-emissive or photocathode layer, 1, incorporated into an entry window 2; the photocathode receives, in operation, the incident radiation, represented by the wavy arrow, and emits at each point a number of electrons proportional to the incident flux received by this point;
  • - an electronic optical device 3, electrostatic or electromagnetic;
  • - a micro-channel plate 4;
  • - a cathodo-luminescent screen 5, an integral part of an exit window 6.

L'optique électronique assure l'accélération et le transfert des électrons émis par chaque point de la photocathode vers un point homologue de la galette 4 ; ce transfert d'électrons s'accompagne d'une inversion d'image, comme le montre le dessin du pinceau d'électrons (flèches courbes, sans repère), correspondant à l'un de ces points.The electronic optics ensures the acceleration and the transfer of the electrons emitted by each point of the photocathode towards a homologous point of the wafer 4; this electron transfer is accompanied by an image inversion, as shown by the brush drawing of electrons (curved arrows, without mark), corresponding to one of these points.

Le dispositif d'optique électronique se compose de plusieurs éleetrodes dont on a représenté sur la figure les deux principales, à savoir l'électrode de focalisation et d'électrode de correction ; ces électrodes portent les repères 30 et 31 respectivement.The electronic optical device is made up of several electrodes, the two main ones of which have been shown in the figure, namely the focusing electrode and the correction electrode; these electrodes bear the marks 30 and 31 respectively.

A la sortie de chaque canal , les électrons secondaires sont accélérés et focalisés vers les différents )oints de l'écran luminescent par un champ électrique établi entre la galette 4 et l'écran 5 ; la figure montre, sans repère, le cône d'impact,sur l'écran,des électrons d'un canal, cône dont on a, pour la clarté, volontairement exagéré l'angle au sommet. Ces impacts forment sur l'écran une image lumineuse correspondant à l'image incidente.At the output of each channel, the secondary electrons are accelerated and focused towards the different) anointed with the luminescent screen by an electric field established between the wafer 4 and the screen 5; the figure shows, without reference mark, the cone of impact, on the screen, of the electrons of a channel, cone of which we have, for clarity, deliberately exaggerated the angle at the top. These impacts form on the screen a bright image corresponding to the incident image.

L'ensemble des éléments ci-dessus forme le tube intensificateur d'images 10, dont l'enveloppe à vide porte le repère 20.All of the above elements form the image intensifier tube 10, the vacuum envelope of which bears the mark 20.

On n'a pas précisé sur les dessins la structure de la fenêtre d'entrée,ni celle de la fenêtre de sortie du tube. On n'en a retenu que la présence de la photocathode dans la première et de l'écran luminescente dans la deuxième, entre lesquelles à lieu le trajet des électrons produits par la photocathode, ou photo-électrons, et qui sont les seuls éléments nécessaires à la compréhension de l'invention. Ces fenêtres peuvent comprendre d'autres éléments, comme des plaquettes de fibres optiques ou des scintillateurs dans le cas de rayonnements incidents en dehors du spectre visible, comme connu de l'art.The structure of the inlet window and that of the tube outlet window have not been specified in the drawings. We only retained the presence of the photocathode in the first and of the luminescent screen in the second, between which takes place the path of the electrons produced by the photocathode, or photoelectrons, and which are the only elements necessary understanding the invention. These windows may include other elements, such as optical fiber wafers or scintillators in the case of incident radiation outside the visible spectrum, as known in the art.

De même on a omis volontairement la repré- sentationdes sources de tension utilisées en fonctionnement dans le but de simplifier les figures. Par contre, on précisera ci-dessous, sur un exemple, la répartition des potentiels dans un tel tube.Likewise, we have deliberately omitted the representation of the voltage sources used as a function in order to simplify the figures. On the other hand, an example will be given below, the distribution of the potentials in such a tube.

Un tel tube permet d'obtenir sur son écran de sortie une image à luminance élevée, grâce à l'énergie communiquéeaux électrons par les potentiels appliqués d'une part, et à la multiplication assurée par la galette de micro-canaux d'autre part.Cette propriété est utilisée dans de nombreux dispositifs pour l'observation de scènes faiblement éclairées, les scènes nocturnes notamment.Such a tube makes it possible to obtain on its output screen an image with high luminance, thanks to the energy communicated to electrons by the potentials applied on the one hand, and to the multiplication ensured by the wafer of micro-channels on the other hand This property is used in many devices for the observation of dimly lit scenes, particularly night scenes.

Dans l'art antérieur, pour pallier les inconvénients signalés plus haut, on met à profil la distribution des potentiels sur'ces différentes électrodes et notamment celles de la section de transfert, comprise entre la photocathode et la galette de micro-canaux, distribution qui fait que les ions créés dans-les micro-canaux ne peuvent atteindre en grand nombre la photocathode.In the prior art, to overcome the drawbacks mentioned above, the distribution of the potentials on these different electrodes and in particular those of the transfer section, included between the photocathode and the micro-channel plate, is profiled. the fact that the ions created in the microchannels cannot reach the photocathode in large numbers.

Le diagramme de la figure 2 donne un exemple, parmi les plus courants, de cette distribution des potentiels dans un tube intensificateur tel que celui décrit ; les repères sont utilisés ici pour désigner les niveaux moyens des électrodes de la figure précédente.The diagram in FIG. 2 gives one of the most common examples of this distribution of potentials in an intensifier tube such as that described; the marks are used here to designate the average levels of the electrodes of the previous figure.

Les électrons émis par la photocathode sont d'abord accélérés puis légèrement ralentis, mais atteignent l'entrée des micro-canaux avec une accélération positive ; par contre,les ions créés dans ces micro-canaux, et dont le potentiel est au plus égal à celui de la face 42 de sortie(pour les électrons) de la galette 4, sont ralentis entre la face opposée, d'entrée, 40 de celle-ci et l'électrode de focalisation 30 ; leur énergie est insuffisante pour qu'ils atteignent cette électrode, qui les repousse vers la galette de micro-canaux, vers les parois de l'enceinte 20 et plus particulièrement vers l'électrode de correction 31, dont le potentiel est le plus négatif. Ils n'arrivent pas à franchir le sommet A du profil de potentiel.The electrons emitted by the photocathode are first accelerated then slightly slowed down, but reach the entry of the micro-channels with a positive acceleration; on the other hand, the ions created in these micro-channels, and whose potential is at most equal to that of the exit face 42 (for the electrons) of the wafer 4, are slowed down between the opposite face, entry, 40 thereof and the focusing electrode 30; their energy is insufficient for them to reach this electrode, which pushes them back towards the micro-channel wafer, towards the walls of the enclosure 20 and more particularly towards the correction electrode 31, the potential of which is the most negative. They fail to cross the top A of the potential profile.

On rappelle que le rôle de l'électrode de correction 31 est d'uniformiser l'angle d'incidence des pinceaux d'électrons sur la galette de micro-canaux,afin d'uniformiser le gain, et de réduire la distorsion de l'image.It is recalled that the role of the correction electrode 31 is to standardize the angle of incidence of the electron brushes on the wafer of micro-channels, in order to standardize the gain, and to reduce the distortion of the picture.

La disposition précédente a le mérite d'éviter la dégradation de la photocathode par une partie des ions présents dans le tube ; par contre elle ne limite pas l'élévation dé la pression dans le tube consécutive à l'apparition de ces ions et qui à indirectement les mêmes effets.. Selon l'invention, pour limiter cette élévation, un matériau getter est disposé sur les parties du tube vers lesquelles se dirigent préférentiellement les ions situées dans la dernière partie du trajet suivi par les élections, en particulier sur l'électrode de correction 31 et sur la surface de l'électrode dé focalisatin 30 en regard de la plaquette de micro-canaux 4, de l'exemple décrit, dans les conditions qui vont être exposées.The previous arrangement has the advantage of avoiding the degradation of the photocathode by a part of the ions present in the tube; on the other hand it does not limit the rise in pressure in the tube following the appearance of these ions and which indirectly has the same effects. According to the invention, to limit this rise, a getter material is placed on the parts of the tube to which the ions located in the last part of the path followed by the elections preferentially go, in particular on the correction electrode 31 and on the surface of the focalization electrode 30 facing the micro-channel plate 4, of the example described, under the conditions which will be explained.

La figure 3 montre, à titre non limitatif, un exemple de réalisation de l'invention ; sur cette figure, la partie gauche, 3(a) représente une demi-coupe d'un intensificateur d'images à micro-canaux de l'art connu, et la partie droite, 3(b) l'autre demi-coupe du même tube modifié par l'invention. La figure montre trois modifications possibles, mais non nécessairement réalisées simultanément dans un même tube de l'invention.Figure 3 shows, without limitation, an embodiment of the invention; in this figure, the left part, 3 (a) represents a half-section of a micro-channel image intensifier of the known art, and the right part, 3 (b) the other half-section of the same tube modified by the invention. The figure shows three possible modifications, but not necessarily carried out simultaneously in the same tube of the invention.

Par contre dans le cas où le tube comporterait d'avantage d'électrodes que celui de l'exemple, dans son système optique notamment, des modifications telles que celles décrites pourraient être appliquées, dans le cadre de l'invention, aux diveres électrodes.On the other hand, in the case where the tube would have more electrodes than that of the example, in its optical system in particular, modifications such as those described could be applied, in the context of the invention, to the various electrodes.

Comme le montre le dessin , l'électrode de focalisation 30 est modifiée de manière à permettre l'alimentation électrique d'un getter ; elle est prévue en deux parties 301 et 302 ; le getter 50, est placé entre ces deux parties, avantageusement recourbées de façon à servir de masques protégeant contre l'évaporation les différentes parties constitutives 21- 24 de l'enveloppe isolante 20, ainsi que la plaquette de micro-canaux 4, d'un côté et la photocathode 1 de 1' l'autre, dans le cas où il s'agit d'un getter évaporable au tantale, titane, baryum, etc. La même disposition peut être utilisée dans le cas d'un getter non évaporable, à oxyde de zirconium aluminium par exemple ; dans ce cas le getter est alimenté entre les deux parties de l'électrode auquelles il sert de liaison électrique,par des connexions,51 et 52 sur la figure.As shown in the drawing, the focusing electrode 30 is modified so as to allow the electrical supply of a getter; it is provided in two parts 301 and 302; the getter 50 is placed between these two parts, advantageously curved so as to serve as masks protecting against evaporation the various constituent parts 21-24 of the insulating envelope 20, as well as the micro-channel plate 4, of one side and photocathode 1 on the other, in the case of an evaporable getter with tantalum, titanium, barium, etc. The same arrangement can be used in the case of a non-evaporable getter, with aluminum zirconium oxide for example; in this case the getter is supplied between the two parts of the electrode to which it serves as an electrical connection, by connections, 51 and 52 in the figure.

De la même manière, un autre getter est disposé au niveau de l'électrode de correction 31 faite, elle aussi, en deux parties 311 et 312 préférentiellement recourbées pour les mêmes raisons ; le getter porte le repère 60 sur les figures et ses connexions les repères 61 et 62.In the same way, another getter is arranged at the level of the correction electrode 31 also made in two parts 311 and 312 preferably bent for the same reasons; the getter carries the mark 60 in the figures and its connections the marks 61 and 62.

L'art antérieur prévoit dans certains cas de loger un getter 80 au niveau de la connexion de photocahode, connexion qui consiste, selon une pratique répandue, en une coupelle 70 soudée à la fenêtre d'entrée 2 ; ce getter est alimenté à travers le queusot 90 par le passage 100. En outre un écran 110 est prévu pour protéger la photocathode proche contre l'évaporation du getter. En opposition avec cet art antérieur, l'invention prévoit, de se passer d'un tel getter, qui se trouve placé a un endroit du tube ou la formation d'ions est peu problable. L'embout, ou connexion de cathode se trouve ainsi simplifié et son diamètre réduit,toutes choses égales par ailleurs,par rapport au cas des tubes de l'art antérieur. Une telle réduction de l'encombrement radial des tubes constitue un avantage de l'invention.The prior art provides in some cases for housing a getter 80 at the photocahode connection, connection which consists, according to widespread practice, in a cup 70 welded to the input window 2; this getter is fed through the queusot 90 through the passage 100. In addition, a screen 110 is provided to protect the near photocathode against evaporation of the getter. In contrast to this prior art, the invention provides, to pass from such a getter, which is placed at a place in the tube where the formation of ions is unlikely. The tip, or cathode connection is thus simplified and its diameter reduced, all other things being equal, compared to the case of tubes of the prior art. Such a reduction in the radial size of the tubes constitutes an advantage of the invention.

De tels tubes sont utilisés également en radiologie médicale pour réduire l'intensité de l'irradiation X, où ils sont connus sous le nom d'intensifica- teurs d'images radiologiques (11R). Dans le cas, la fenêtre d'entrée comporte,devant la photocathode,un scintillateur accolé à celle-ci.Such tubes are also used in medical radiology to reduce the intensity of X-ray irradiation, where they are known as X-ray image intensifiers (11R). In this case, the entry window includes, in front of the photocathode, a scintillator attached to it.

Ils sont, aussi, fréquemment incorporés à des chaînes de prise de vues comportant plusieurs autres tubes ; ils sont placés à des niveaux variés dans ces chaînes,dans lesquelles leur rôle est d'accroître le niveau du signal de sortie.They are also frequently incorporated into shooting chains comprising several other tubes; they are placed at various levels in these chains, in which their role is to increase the level of the output signal.

L'invention couvre également de tels ensembles.The invention also covers such assemblies.

Claims (5)

1. Tube intensificateur d'images comprenant, situées aux extrémités d'une enceinte à vide (20), une fenêtre d'entrée (2) et une fenêtre de sortie (6) auxquelles sont incorporées respectivement une photocathode (1)et un écran luminescent (5), laquelle fenêtre d'entrée est exposée, en fonctionnement, au rayonnement en provenance de l'image, et comprenant, disposé entre ces deux fenêtres, un système d'électrodes (3)assurant l'accélération vers l'écran des électrons émis par le photocathode sous l'effet de ce rayonnement, l'impact de ces photo-électrons sur l'écran formant une image correspondant à l'image incidente, ledit tube comprenant, en outre, un élément à micro-canaux (4) placé devant l'écran et dans sa proximité, caractérisé en ce que ledit tube comporte des getters (50, 60) disposés sur certaines de ces électrodes, à leur périphérie, notamment dans la dernière partie du trajet des photo-électrons.1. Image intensifier tube comprising, situated at the ends of a vacuum enclosure (20), an inlet window (2) and an outlet window (6) into which are respectively incorporated a photocathode (1) and a screen luminescent (5), which entry window is exposed, in operation, to radiation from the image, and comprising, arranged between these two windows, a system of electrodes (3) ensuring acceleration towards the screen electrons emitted by the photocathode under the effect of this radiation, the impact of these photo-electrons on the screen forming an image corresponding to the incident image, said tube further comprising a micro-channel element ( 4) placed in front of the screen and in its proximity, characterized in that said tube comprises getters (50, 60) arranged on some of these electrodes, at their periphery, in particular in the last part of the path of the photoelectrons. 2. Tube intensificateur d'images suivant la revendication l,caractérisé en ce que, le système en question comportant une électrode de focalisation (30) et une électrode de correction (31) se succédant sur le trajet du faisceau, il comprend un getter disposé sur chacune de ces deux électrodes.2. image intensifier tube according to claim l, characterized in that, the system in question comprising a focusing electrode (30) and a correction electrode (31) succeeding each other in the beam path, it comprises a getter disposed on each of these two electrodes. 3. Tube intensificateur d'images suivant la revendication 1, caractérisé en ce que chaque électrode sur laquelle est disposé un getter est faite de deux parties électriquement isolées l'une de l'autre (301, 302 - 311, 312) entre lesquelles est monté le getter.3. Image intensifier tube according to claim 1, characterized in that each electrode on which a getter is arranged is made of two parts electrically insulated from one another (301, 302 - 311, 312) between which is mounted the getter. 4. Tube intensificateur d'images suivant la revendication 3, caractérisé en ce que, ces parties sont terminées,vers l'intérieur du tube,par des portions recourbées.4. Image intensifier tube according to claim 3, characterized in that these parts are terminated, towards the inside of the tube, by curved portions. 5. Ensemble de prise de vues, caractérisé en ce qu'il comprend au moins un tube intensificateur d'images suivant l'une des revendications 1, 2, 3 ou 4.5. Shooting assembly, characterized in that it comprises at least one image intensifier tube according to one of claims 1, 2, 3 or 4.
EP81401034A 1980-07-11 1981-06-26 Microchannels image intensifier tube and image pick-up assembly comprising such a tube Expired EP0044239B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8015496 1980-07-11
FR8015496A FR2486712A1 (en) 1980-07-11 1980-07-11 MICRO-CHANNEL IMAGE INTENSIFIER TUBE, AND SHOOTING ASSEMBLY COMPRISING SUCH A TUBE

Publications (2)

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EP0044239A1 true EP0044239A1 (en) 1982-01-20
EP0044239B1 EP0044239B1 (en) 1984-03-14

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP81401034A Expired EP0044239B1 (en) 1980-07-11 1981-06-26 Microchannels image intensifier tube and image pick-up assembly comprising such a tube

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US (1) US4489251A (en)
EP (1) EP0044239B1 (en)
JP (1) JPS5749152A (en)
DE (1) DE3162647D1 (en)
FR (1) FR2486712A1 (en)

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GB2157072A (en) * 1984-03-16 1985-10-16 Getters Spa Image intensifier with an electrophoretic getter

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JP2559578Y2 (en) * 1990-03-28 1998-01-19 株式会社島津製作所 Image intensifier
FR2688343A1 (en) * 1992-03-06 1993-09-10 Thomson Tubes Electroniques INTENSIFYING IMAGE TUBE, IN PARTICULAR RADIOLOGICAL, OF THE TYPE A GALETTE OF MICROCHANNELS.
JP4231123B2 (en) 1998-06-15 2009-02-25 浜松ホトニクス株式会社 Electron tubes and photomultiplier tubes
DE19921766C1 (en) * 1999-05-11 2001-02-01 Siemens Ag X-ray image intensifier and method for its production
JP4832898B2 (en) * 2006-01-04 2011-12-07 浜松ホトニクス株式会社 Electron tube
US10809393B2 (en) * 2015-04-23 2020-10-20 Fermi Research Alliance, Llc Monocrystal-based microchannel plate image intensifier

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BE506756A (en) * 1950-10-30
CH377948A (en) * 1958-02-14 1964-05-31 Rauland Corp Image converter tube
US3868536A (en) * 1971-10-18 1975-02-25 Varian Associates Image intensifier tube employing a microchannel electron multiplier
US3870917A (en) * 1971-05-10 1975-03-11 Itt Discharge device including channel type electron multiplier having ion adsorptive layer
FR2445612A1 (en) * 1978-12-29 1980-07-25 Labo Electronique Physique Image tube with micro-channel pad - sepg. two chambers and with getter material on luminescent screen

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US3100274A (en) * 1959-12-17 1963-08-06 Raytheon Co Electron tube with electrode having titanium surface serving as getter
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BE506756A (en) * 1950-10-30
CH377948A (en) * 1958-02-14 1964-05-31 Rauland Corp Image converter tube
US3870917A (en) * 1971-05-10 1975-03-11 Itt Discharge device including channel type electron multiplier having ion adsorptive layer
US3868536A (en) * 1971-10-18 1975-02-25 Varian Associates Image intensifier tube employing a microchannel electron multiplier
FR2445612A1 (en) * 1978-12-29 1980-07-25 Labo Electronique Physique Image tube with micro-channel pad - sepg. two chambers and with getter material on luminescent screen

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2157072A (en) * 1984-03-16 1985-10-16 Getters Spa Image intensifier with an electrophoretic getter

Also Published As

Publication number Publication date
DE3162647D1 (en) 1984-04-19
EP0044239B1 (en) 1984-03-14
FR2486712B1 (en) 1983-06-10
FR2486712A1 (en) 1982-01-15
US4489251A (en) 1984-12-18
JPS5749152A (en) 1982-03-20

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