EP0544739B1 - Low light level, high resolution imager - Google Patents

Low light level, high resolution imager Download PDF

Info

Publication number
EP0544739B1
EP0544739B1 EP91914906A EP91914906A EP0544739B1 EP 0544739 B1 EP0544739 B1 EP 0544739B1 EP 91914906 A EP91914906 A EP 91914906A EP 91914906 A EP91914906 A EP 91914906A EP 0544739 B1 EP0544739 B1 EP 0544739B1
Authority
EP
European Patent Office
Prior art keywords
light
fact
electron
imager according
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 - Lifetime
Application number
EP91914906A
Other languages
German (de)
French (fr)
Other versions
EP0544739A1 (en
Inventor
Yves Charon
Jean-Marc Gaillard
Michel Leblanc
Roland Mastrippolito
Hervé Tricoire
Luc Valentin
Philippe Laniece
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Centre National de la Recherche Scientifique CNRS
Original Assignee
Centre National de la Recherche Scientifique CNRS
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Centre National de la Recherche Scientifique CNRS filed Critical Centre National de la Recherche Scientifique CNRS
Publication of EP0544739A1 publication Critical patent/EP0544739A1/en
Application granted granted Critical
Publication of EP0544739B1 publication Critical patent/EP0544739B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2231/00—Cathode ray tubes or electron beam tubes
    • H01J2231/50—Imaging and conversion tubes
    • H01J2231/50005—Imaging and conversion tubes characterised by form of illumination
    • H01J2231/5001—Photons
    • H01J2231/50015—Light
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2231/00—Cathode ray tubes or electron beam tubes
    • H01J2231/50—Imaging and conversion tubes
    • H01J2231/50057—Imaging and conversion tubes characterised by form of output stage
    • H01J2231/50063—Optical
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2231/00—Cathode ray tubes or electron beam tubes
    • H01J2231/50—Imaging and conversion tubes
    • H01J2231/50057—Imaging and conversion tubes characterised by form of output stage
    • H01J2231/50089—Having optical stage before electrical conversion
    • H01J2231/50094—Charge coupled device [CCD]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2231/00—Cathode ray tubes or electron beam tubes
    • H01J2231/50—Imaging and conversion tubes
    • H01J2231/501—Imaging and conversion tubes including multiplication stage
    • H01J2231/5013—Imaging and conversion tubes including multiplication stage with secondary emission electrodes
    • H01J2231/5016—Michrochannel plates [MCP]

Definitions

  • the present invention relates to a high resolution imager with low light level according to the first part of claim 1.
  • CCD charge transfer devices
  • the scintillator 20 generates photons when it detects an electron from the sample or an equivalent source.
  • the light is amplified in the tube 30 then applied to the electronic camera 40.
  • This camera 40 is controlled in single shot mode, and not in video mode, by the module 42.
  • the frame cycles (each cycle being composed of a reset phase of the transfer device of loads, an image integration phase, then a reading phase) follow one another at a fixed rate.
  • each frame cycle is controlled independently of the previous cycle.
  • the camera 40 is controlled in repetitive single shot mode by the external trigger generator 60, that is to say that the camera 40 is controlled to present short and repetitive integration cycles, as opposed to a simple single shot mode consisting in integrating the image of the light source over a long period and then reading only at the end of acquisition.
  • Figure 2 shows the time distribution of a light source or sample.
  • FIG. 3 represents the corresponding response of a light amplifier tube 30.
  • the noise pulses will be noted in FIG. 3.
  • the cycles of the charge transfer device 41 are superimposed on the response of the tube 30, each comprising a phase for resetting the CCD to zero, a phase for integrating the image and a CCD reading phase, on the other hand, the signal triggering these cycles.
  • the technique of piloting the camera 30 in single shot mode repetitive overcomes in part the significant cooling required in a repetitive single shot mode due to the contribution of thermal noise from the light amplifier tube and the camera, which is proportional to the integration time.
  • the external trigger generator 60 is replaced by a photomultiplier 80, associated with a shaping card 81.
  • the photomultiplier 80 is arranged opposite the scintillator 20 relative to the sample holder 10. Thus, the photomultiplier recovers part of the photons generated by the scintillator 20, after these have passed through the sample and the sample holder 10, to generate a synchronized trigger pulse on the appearance of a light event.
  • the integration time can be adjusted to a minimum value solely as a function of the phosphorus decay period of the light amplifier tube 30 and the duration of the reset phase of the charge transfer device 41.
  • This system is first of all dependent on the thickness of the sample used. If the sample is too thick, the photonmultiplier 80 receives little or no light.
  • this system is essentially limited to the field of molecular biology experiments, but cannot for example be used in the field of astrophysics.
  • the object of the present invention is to improve the situation by eliminating the drawbacks of the prior art.
  • the imager according to the present invention shown in FIG. 7 appended comprises a light amplifier tube 300, an electronic camera 400, a control circuit 700 and a computer 500.
  • the light amplifier tube 300 is preferably of the proximity focusing type equipped with a double microchannel pancake giving a high gain.
  • This tube 300 essentially comprises, as shown in the appended FIG. 7: a photocathode 310, two wafers 330, 331 to microchannels serving as an electron amplifier, and a phosphor screen 340, forming an anode.
  • the phosphor screen 340 more precisely comprises a phosphor layer 341, covered, on the wafer side 330, 331, with a thin metallic layer 342, generally aluminum.
  • the spray of secondary electrons corresponding to the amplification of a photoelectron by the wafers 330, 331 is accelerated towards the screen 340.
  • the electrons are slowed down in this screen, there is production of light by the medium 341 excited, and the electrons are collected in a few ns on the metallized face 342 of the screen.
  • the electron / electron gain of a tube 300 with double wafers 330, 331 is typically of the order of 105.
  • the control circuit 700 comprises an amplifier 710 sensitive to the electrons collected on the metal layer of the screen 340 to control the integration cycles of the camera 400, via of a door 714.
  • the function of this door 714 is to transform the analog signal from the amplifier 710 into a logic signal.
  • Gate 714 essentially proceeds by integration and comparison with a threshold. It may, for example, be the integrating linear door sold by the company SEPH.
  • Gate 714 is placed between the output of amplifier 710 and the input of module 420.
  • the metal layer 342 of the screen is connected to ground through a resistor R712 and the metal layer 342 is connected to a first input of the operational amplifier 710 , while the second input of it is connected to ground.
  • This voltage is amplified by the voltage amplifier 710.
  • the latter is of the low noise and wide bandwidth type.
  • the signal is then integrated under load and then subjected to a voltage threshold, in gate 714, the validation of which constitutes the trigger signal applied to the module 420.
  • the electronic camera 400 used in the context of the present invention advantageously comprises a charge transfer device (CCD) 410, a pilot module 420 and a module 430 for shaping the signals picked up on the CCD, in a similar manner to the systems previously known, previously described with reference to FIGS. 1 and 5.
  • CCD charge transfer device
  • the trigger signal from gate 714 is then applied to the input of the pilot module 420, so that each trigger signal initiates a reset or "wash" cycle of the CCD, of integration of the image on the CCD, then read it via the module 430.
  • the signals thus obtained then pass through an interface card 720 before being directed to the computer 500 or they are processed in a manner known per se, as described in the prior documents previously described.
  • the phosphor screen 340 must have a period compatible with the duration of resetting the CCD 410. This screen must memorize the image during the resetting of the CCD which precedes each integration.
  • the imager according to the present invention makes it possible to produce an image of a very weak light source (sensitivity to the single photoelectron) with a resolution of the order of 20 ⁇ m.
  • CCD charge transfer device
  • a charge transfer device is a matrix network of around 104 small photosensitive cells (around 20x20 ⁇ m) capable of transforming each received photon into electron.
  • Each cell accumulates during the integration phase, a quantity of charges proportional to the illumination it receives.
  • the stage reading consists in sequentially transferring the content of each cell to an imaging device (in this case preferably the computer 500, via the interface card 720).
  • the charge transfer device 410 can be replaced by a CID type device known to those skilled in the art in which the charges accumulated in each cell are read directly without transfer .
  • the inventors notably carried out tests using an imager comprising a tube 300 light amplifier with proximity focusing equipped with a double microchannel wafer 330, 331 to obtain an electron / electron gain of the order of 105 and a fast phosphor screen (P47), a 400 CCD electronic camera, a low noise ( ⁇ 5 mV) wide bandwidth 710 voltage amplifier (of the order of 200 MHz) having a voltage gain of 100 , and an integrating linear door 714 sold by the company SEPH.
  • an imager comprising a tube 300 light amplifier with proximity focusing equipped with a double microchannel wafer 330, 331 to obtain an electron / electron gain of the order of 105 and a fast phosphor screen (P47), a 400 CCD electronic camera, a low noise ( ⁇ 5 mV) wide bandwidth 710 voltage amplifier (of the order of 200 MHz) having a voltage gain of 100 , and an integrating linear door 714 sold by the company SEPH.
  • the imager previously described is designed to detect incident light photons.
  • the imager can however easily be adapted to detect other types of incident rays, such as for example ⁇ ⁇ rays by placing a system for converting these incident rays into light, such as a scintillator 200, upstream of the tube 300 , as shown in broken lines in Figure 7.
  • a system for converting these incident rays into light such as a scintillator 200, upstream of the tube 300 , as shown in broken lines in Figure 7.

Landscapes

  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
  • Transforming Light Signals Into Electric Signals (AREA)
  • Measurement Of Radiation (AREA)
  • Common Detailed Techniques For Electron Tubes Or Discharge Tubes (AREA)
  • Nuclear Medicine (AREA)

Abstract

PCT No. PCT/FR91/00680 Sec. 371 Date Apr. 16, 1993 Sec. 102(e) Date Apr. 16, 1993 PCT Filed Aug. 21, 1991 PCT Pub. No. WO92/03836 PCT Pub. Date Mar. 5, 1992.The present invention relates to a low level, high resolution imager of the type comprising a light-amplifier tube (300) including a photocathode (310), at least one microchannel slab (330) serving as an electron amplifier, and a light-emitting phosphor screen (340) provided with a metal layer (342), an electron camera (400) comprising a photosensitive matrix array (410) suitable for transforming a received photon into an electron, and control means (700) for the electron camera, characterized by the fact that the control means (700) comprise an amplifier (710) responsive to the electrons collected on the metal layer (342) of the light-emitting phosphor screen (340) to control integration cycles of the photosensitive matrix array (410) in repetitive one-shot mode synchronized on the appearance of photons at the input of the light-amplifying tube (300).

Description

La présente invention concerne un imageur haute résolution à bas niveau de lumière selon la première partie de la revendication 1.The present invention relates to a high resolution imager with low light level according to the first part of claim 1.

Un grand nombre de travaux en physique (nucléaire, astrophysique, biophysique) nécessitent de pouvoir localiser avec une grande précision des sources lumineuses très faibles au niveau du comptage de photons.A large number of works in physics (nuclear, astrophysics, biophysics) require to be able to locate with great precision very weak light sources at the level of photon counting.

Par exemple, de nombreux travaux réalisés en biologie moléculaire tirent leur information de l'étude de la localisation spatiale d'espèces chimiques (brins d'ADN ou d'ARN). Pour ce faire, la technique couramment utilisée consiste à marquer l'espèce étudiée à l'aide d'une sonde spécifique radioactive. L'expression d'un résultat expérimental se résume alors à une cartographie plus ou moins fine, quantitative ou non, de populations d'émetteurs β ⁻.For example, many works carried out in molecular biology draw their information from the study of the spatial localization of chemical species (strands of DNA or RNA). To do this, the commonly used technique consists in marking the species studied using a specific radioactive probe. The expression of an experimental result then comes down to a more or less fine mapping, quantitative or not, of populations of β ⁻ emitters.

On a proposé depuis plusieurs années de recueillir l'image des sources lumineuses sur des dispositifs à transfert de charges (CCD).It has been proposed for several years to collect the image of light sources on charge transfer devices (CCD).

On a décrit par exemple dans le document Nuclear Instruments and Methods in Physics Research A 273 (1988) 748-753, "A high resolution β ⁻ detector", Y CHARON et al, un système, schématiquement illustré sur la figure 1 annexée, particulièrement adapté à des expérimentations en biologie moléculaire et qui comprend :

  • un porte-échantillon 10,
  • un scintillateur 20, mince (10µ)
  • un tube amplificateur de lumière 30 comportant essentiellement :
    • . une photocathode 31,
    • . des électrodes de focalisation 32,
    • . une galette 33 à microcanaux amplificatrice d'électrons par émission secondaire,
      et
    • . un écran phosphore luminescent 34,
  • une caméra électronique 40 comprenant
    • . un dispositif à transfert de charges (CCD) 41,
    • . un module pilote 42, et
    • . un module de mise en forme 43,
  • un ordinateur d'exploitation 50,
  • un générateur de déclenchement externe 60,
    et
  • une carte 70 d'interface entre le générateur 60, la caméra 40 et l'ordinateur 50.
We have described for example in the document Nuclear Instruments and Methods in Physics Research A 273 (1988) 748-753, "A high resolution β ⁻ detector", Y CHARON et al, a system, schematically illustrated in Figure 1 attached, particularly suitable for experiments in molecular biology and which includes:
  • a sample holder 10,
  • a scintillator 20, thin (10µ)
  • a light amplifier tube 30 essentially comprising:
    • . a photocathode 31,
    • . focusing electrodes 32,
    • . a wafer 33 with electron-amplifying microchannels by secondary emission,
      and
    • . a luminescent phosphor screen 34,
  • an electronic camera 40 comprising
    • . a charge transfer device (CCD) 41,
    • . a pilot module 42, and
    • . a shaping module 43,
  • an operating computer 50,
  • an external trigger generator 60,
    and
  • an interface card 70 between the generator 60, the camera 40 and the computer 50.

Le scintillateur 20 génère des photons quand il détecte un électron en provenance de l'échantillon ou d'une source équivalente. La lumière est amplifiée dans le tube 30 puis appliquée à la caméra électronique 40.The scintillator 20 generates photons when it detects an electron from the sample or an equivalent source. The light is amplified in the tube 30 then applied to the electronic camera 40.

Cette caméra 40 est pilotée en mode monocoup, et non pas en mode vidéo, par le module 42. Dans un mode de commande vidéo, les cycles-trames (chaque cycle étant composé d'une phase de remise à zéro du dispositif à transfert de charges, d'une phase d'intégration de l'image, puis d'une phase de lecture) se succèdent à cadence fixe. En revanche, dans un mode de commande monocoup, chaque cycle-trame est piloté indépendamment du cycle précédent.This camera 40 is controlled in single shot mode, and not in video mode, by the module 42. In a video control mode, the frame cycles (each cycle being composed of a reset phase of the transfer device of loads, an image integration phase, then a reading phase) follow one another at a fixed rate. On the other hand, in a single shot control mode, each frame cycle is controlled independently of the previous cycle.

Plus précisément encore, selon le document précité, la caméra 40 est pilotée en mode monocoup répétitif par le générateur de déclenchement externe 60, c'est-à-dire que la caméra 40 est pilotée pour présenter des cycles d'intégration courts et répétitifs, par opposition à un mode monocoup simple consistant à intégrer l'image de la source lumineuse sur une période longue puis à lire uniquement en fin d'acquisition.More precisely still, according to the aforementioned document, the camera 40 is controlled in repetitive single shot mode by the external trigger generator 60, that is to say that the camera 40 is controlled to present short and repetitive integration cycles, as opposed to a simple single shot mode consisting in integrating the image of the light source over a long period and then reading only at the end of acquisition.

Le pilotage de la caméra 40 est schématisé sur les figures 2, 3 et 4 annexées.The control of camera 40 is shown diagrammatically in Figures 2, 3 and 4 attached.

La figure 2 représente la distribution temporelle d'une source lumineuse ou échantillon.Figure 2 shows the time distribution of a light source or sample.

La figure 3 représente la réponse correspondante d'un tube amplificateur de lumière 30. On notera la présente d'impulsions de bruit sur la figure 3.FIG. 3 represents the corresponding response of a light amplifier tube 30. The noise pulses will be noted in FIG. 3.

Enfin, sur la figure 4 on a superposé à la réponse du tube 30, d'une part les cycles du dispositif à transfert de charges 41 comprenant chacun une phase de remise à zéro du CCD, une phase d'intégration de l'image et une phase de lecture du CCD, d'autre part le signal déclencheur de ces cycles.Finally, in FIG. 4, the cycles of the charge transfer device 41 are superimposed on the response of the tube 30, each comprising a phase for resetting the CCD to zero, a phase for integrating the image and a CCD reading phase, on the other hand, the signal triggering these cycles.

La technique de pilotage de la caméra 30 en mode monocoup répétitif permet de s'affranchir en partie du refroidissement important exigé dans un mode monocoup répétitif en raison de la contribution du bruit thermique du tube amplificateur de lumière et de la caméra, qui est proportionnel au temps d'intégration.The technique of piloting the camera 30 in single shot mode repetitive overcomes in part the significant cooling required in a repetitive single shot mode due to the contribution of thermal noise from the light amplifier tube and the camera, which is proportional to the integration time.

Toutefois, le pilotage de la caméra 30 en mode monocoup répétitif ne donne pas totalement satisfaction. Il présente en effet les inconvénients suivants :

  • des évènements sont perdus durant le temps mort entraînant une perte d'efficacité.
  • la contribution du bruit thermique du tube amplificateur reste importante compte tenu de la durée d'intégration.
  • l'information quantitative d'éclairement du pixel n'est pas exploitable car l'évènement intervient aléatoirement dans la fenêtre d'intégration.
However, piloting the camera 30 in repetitive single shot mode is not entirely satisfactory. It has the following disadvantages:
  • events are lost during the time out resulting in a loss of efficiency.
  • the contribution of the thermal noise of the amplifier tube remains significant taking into account the integration time.
  • the quantitative information on the pixel illumination cannot be used because the event occurs randomly in the integration window.

On a tenté d'éliminer ces inconvénients en ne déclenchant le cycle d'intégration du dispositif à transfert de charges qu'en présence d'un évènement lumineux.We tried to eliminate these drawbacks by only triggering the integration cycle of the charge transfer device in the presence of a light event.

Le système ainsi proposé est décrit dans le document "H.R.R.I. A high resolution β ⁻ imager for biological applications", Nuclear Instruments and Methods in Physics Research A 292 (1990) 179-186, Y. CHARON et al. Ce système est par ailleurs schématisé sur la figure 5 annexée.The system thus proposed is described in the document "H.R.R.I. A high resolution β ⁻ imager for biological applications", Nuclear Instruments and Methods in Physics Research A 292 (1990) 179-186, Y. CHARON et al. This system is also shown schematically in Figure 5 attached.

On retrouve sur la figure 5 :

  • le porte-échantillon 10,
  • le scintillateur 20,
  • le tube amplificateur de lumière 30,
  • la caméra électronique 40,
  • l'ordinateur d'exploitation 50, et
  • la carte d'interface 70.
We find in Figure 5:
  • the sample holder 10,
  • the scintillator 20,
  • the light amplifier tube 30,
  • the electronic camera 40,
  • the operating computer 50, and
  • the interface card 70.

Cependant, selon le système représenté sur la figure 5, le générateur de déclenchement externe 60, est remplacé par un photomultiplicateur 80, associé à une carte de mise en forme 81.However, according to the system shown in FIG. 5, the external trigger generator 60 is replaced by a photomultiplier 80, associated with a shaping card 81.

Le photomultiplicateur 80 est disposé à l'opposé du scintillateur 20 par rapport au porte-échantillon 10. Ainsi, le photomultiplicateur récupère une partie des photons générés par le scintillateur 20, après que ceux-ci aient traversé l'échantillon et le porte-échantillon 10, pour générer une impulsion de déclenchement synchronisée sur l'apparition d'un évènement lumineux.The photomultiplier 80 is arranged opposite the scintillator 20 relative to the sample holder 10. Thus, the photomultiplier recovers part of the photons generated by the scintillator 20, after these have passed through the sample and the sample holder 10, to generate a synchronized trigger pulse on the appearance of a light event.

Le temps d'intégration peut être ajusté à une valeur minimale uniquement fonction de la période de décroissance du phosphore du tube amplificateur de lumière 30 et de la durée de la phase de remise à zéro du dispositif à transfert de charges 41.The integration time can be adjusted to a minimum value solely as a function of the phosphorus decay period of the light amplifier tube 30 and the duration of the reset phase of the charge transfer device 41.

Les cycles ainsi obtenus et les signaux déclencheurs correspondants sont schématisés sur la figure 6 annexée.The cycles thus obtained and the corresponding trigger signals are shown diagrammatically in FIG. 6 appended.

L'examen comparé des figures 4 et 6 montre que le système à déclenchement synchronisé sur l'apparition d'un évènement lumineux, tel que représenté sur la figure 5, offre les avantages suivants :

  • I'efficacité de détection est considérablement accrue.
  • la contribution de bruit thermique, qui intervient aléatoirement dans la fenêtre d'intégration est fortement réduite par la diminution du temps d'intégration.
  • I'intensité d'éclairement est fidèlement restituée, permettant ainsi les traitements de criblage et barycentrage.
The comparative examination of FIGS. 4 and 6 shows that the system with synchronized triggering on the appearance of a light event, as represented in FIG. 5, offers the following advantages:
  • The detection efficiency is considerably increased.
  • the contribution of thermal noise, which occurs randomly in the integration window is greatly reduced by the reduction in the integration time.
  • The intensity of illumination is faithfully restored, thus allowing screening and barycentering treatments.

Toutefois, le système représenté sur la figure 5 ne donne pas non plus totalement satisfaction.However, the system shown in Figure 5 is not entirely satisfactory either.

Ce système est tout d'abord tributaire de l'épaisseur de l'échantillon utilisé. Si l'échantillon est trop épais, le photonmultiplicateur 80 reçoit peu ou pas de lumière.This system is first of all dependent on the thickness of the sample used. If the sample is too thick, the photonmultiplier 80 receives little or no light.

Par ailleurs, ce système est limité essentiellement au domaine des expérimentations en biologie moléculaire, mais ne peut par exemple être utilisé dans le domaine de l'astrophysique.Furthermore, this system is essentially limited to the field of molecular biology experiments, but cannot for example be used in the field of astrophysics.

La présente invention a pour but d'améliorer la situation en éliminant les inconvénients de la technique antérieure.The object of the present invention is to improve the situation by eliminating the drawbacks of the prior art.

Ce but est atteint selon la présente invention, grâce à un imageur haute résolution à bas niveau de lumière, du type comprenant :

  • un tube amplificateur de lumière comportant :
    • . une photocathode,
    • . au moins une galette à microcanaux servant d'amplificateur d'électrons, et
    • . un écran de phosphore luminescent muni d'une couche métallique,
  • une caméra électronique comprenant un réseau matriciel photosensible apte à transformer un photon reçu en électron, et
  • des moyens de commande de la caméra électronique,

caractérisé par le fait que les moyens de commande comprennent un amplificateur sensible aux électrons collectés sur la couche métallique de l'écran phosphore luminescent pour piloter les cycles d'intégration du réseau matriciel photosensible en mode monocoup répétitif synchronisé sur l'apparition de photons à l'entrée du tube amplificateur de lumière.This object is achieved according to the present invention, thanks to a high resolution imager with low light level, of the type comprising:
  • a light amplifier tube comprising:
    • . a photocathode,
    • . at least one microchannel pancake serving as an electron amplifier, and
    • . a luminescent phosphor screen provided with a metallic layer,
  • an electronic camera comprising a photosensitive matrix array capable of transforming a received photon into an electron, and
  • means for controlling the electronic camera,

characterized by the fact that the control means comprise an amplifier sensitive to the electrons collected on the metal layer of the luminescent phosphor screen to control the integration cycles of the photosensitive matrix network in repetitive single-shot mode synchronized on the appearance of photons at l entry of the light amplifier tube.

Des modes particuliers de réalisation de l'invention sont indiqués dans les revendications dépendantes.Particular embodiments of the invention are indicated in the dependent claims.

D'autres caractéristiques, buts et avantages de la présente invention apparaîtront à la lecture de la description détaillée qui va suivre, et en regard des dessins annexés, donnés à titre d'exemples non limitatifs et sur lesquels :

  • la figure 1 précédemment décrite, représente schématiquement un premier système antérieurement connu,
  • la figure 2 représente la distribution temporelle d'une source lumineuse,
  • la figure 3 représente la réponse correspondante collectée à la sortie d'un tube amplificateur de lumière,
  • la figure 4 représente les cycles et le signal déclencheur du système illustré sur la figure 1,
  • la figure 5 précédemment décrite, représente schématiquement un second système antérieurement connu,
  • la figure 6 représente les cycles et le signal déclencheur du système illustré sur la figure 5, et
  • la figure 7 représente schématiquement, sous forme de blocs fonctionnels, un imageur conforme à la présente invention.
Other characteristics, aims and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings, given by way of nonlimiting examples and in which:
  • FIG. 1, previously described, schematically represents a first system previously known,
  • FIG. 2 represents the time distribution of a light source,
  • FIG. 3 represents the corresponding response collected at the output of a light amplifier tube,
  • FIG. 4 represents the cycles and the trigger signal of the system illustrated in FIG. 1,
  • FIG. 5 previously described, schematically represents a second system previously known,
  • FIG. 6 represents the cycles and the trigger signal of the system illustrated in FIG. 5, and
  • FIG. 7 schematically represents, in the form of functional blocks, an imager according to the present invention.

L'imageur conforme à la présente invention représenté sur la figure 7 annexée comprend un tube amplificateur de lumière 300, une caméra électronique 400, un circuit de commande 700 et un ordinateur 500.The imager according to the present invention shown in FIG. 7 appended comprises a light amplifier tube 300, an electronic camera 400, a control circuit 700 and a computer 500.

Le tube amplificateur de lumière 300 est de préférence du type à focalisation de proximité équipé d'une double galette à microcanaux donnant un gain élevé.The light amplifier tube 300 is preferably of the proximity focusing type equipped with a double microchannel pancake giving a high gain.

Ce tube 300 comprend essentiellement comme représenté sur la figure 7 annexée : une photocathode 310, deux galettes 330, 331 à microcanaux servant d'amplificateur d'électrons, et un écran phosphore 340, formant anode.This tube 300 essentially comprises, as shown in the appended FIG. 7: a photocathode 310, two wafers 330, 331 to microchannels serving as an electron amplifier, and a phosphor screen 340, forming an anode.

L'écran phosphore 340 comprend plus précisément une couche de phosphore 341, recouverte, côté galettes 330, 331, d'une mince couche métallique 342, généralement de l'aluminium.The phosphor screen 340 more precisely comprises a phosphor layer 341, covered, on the wafer side 330, 331, with a thin metallic layer 342, generally aluminum.

Ainsi, la gerbe d'électrons secondaires correspondant à l'amplification d'un photoélectron par les galettes 330, 331 est accélérée vers l'écran 340. Lorsque les électrons sont ralentis dans cet écran, il y a production de lumière par le milieu 341 excité, et les électrons sont collectés en quelques ns sur la face métallisée 342 de l'écran.Thus, the spray of secondary electrons corresponding to the amplification of a photoelectron by the wafers 330, 331 is accelerated towards the screen 340. When the electrons are slowed down in this screen, there is production of light by the medium 341 excited, and the electrons are collected in a few ns on the metallized face 342 of the screen.

Le gain électrons/électrons d'un tube 300 à double galettes 330, 331 est typiquement de l'ordre de 10⁵.The electron / electron gain of a tube 300 with double wafers 330, 331 is typically of the order of 10⁵.

Comme indiqué précédemment selon une caractéristique essentielle de la présente invention, le circuit de commande 700 comprend un amplificateur 710 sensible aux électrons collectés sur la couche métallique de l'écran 340 pour piloter les cycles d'intégration de la caméra 400, par l'intermédiaire d'une porte 714. Cette porte 714 a pour fonction de transformer le signal analogique issu de l'amplificateur 710 en signal logique. La porte 714 procède essentiellement par intégration et comparaison avec un seuil. Il peut s'agir par exemple de la porte linéaire intégratrice commercialisée par la Société SEPH. La porte 714 est placée entre la sortie de l'amplificateur 710 et l'entrée du module 420.As indicated previously according to an essential characteristic of the present invention, the control circuit 700 comprises an amplifier 710 sensitive to the electrons collected on the metal layer of the screen 340 to control the integration cycles of the camera 400, via of a door 714. The function of this door 714 is to transform the analog signal from the amplifier 710 into a logic signal. Gate 714 essentially proceeds by integration and comparison with a threshold. It may, for example, be the integrating linear door sold by the company SEPH. Gate 714 is placed between the output of amplifier 710 and the input of module 420.

Plus précisément, selon le mode de réalisation préférentiel représenté sur la figure 7, la couche métallique 342 de l'écran est reliée à la masse à travers une résistance R712 et la couche métallique 342 est reliée à une première entrée de l'amplificateur opérationnel 710, tandis que la seconde entrée de celui-ci est reliée à la masse.More specifically, according to the preferred embodiment shown in Figure 7, the metal layer 342 of the screen is connected to ground through a resistor R712 and the metal layer 342 is connected to a first input of the operational amplifier 710 , while the second input of it is connected to ground.

Le transit des charges à travers la résistance R712 sert ainsi à générer une différence de potentiel à l'entrée de l'amplificateur 710.The transit of the charges through the resistor R712 thus serves to generate a potential difference at the input of the amplifier 710.

Cette tension est amplifiée par l'amplificateur de tension 710. Ce dernier est du type à bas bruit et large bande passante. Le signal est alors intégré en charge puis soumis à un seuil en tension, dans la porte 714, dont la validation constitue le signal de déclenchement appliqué au module 420.This voltage is amplified by the voltage amplifier 710. The latter is of the low noise and wide bandwidth type. The signal is then integrated under load and then subjected to a voltage threshold, in gate 714, the validation of which constitutes the trigger signal applied to the module 420.

La caméra électronique 400 utilisée dans le cadre de la présente invention comprend avantageusement un dispositif à transfert de charges (CCD) 410, un module pilote 420 et un module 430 de mise en forme des signaux captés sur le CCD, de façon similaire aux systèmes antérieurement connus, précédemment décrits en regard des figures 1 et 5.The electronic camera 400 used in the context of the present invention advantageously comprises a charge transfer device (CCD) 410, a pilot module 420 and a module 430 for shaping the signals picked up on the CCD, in a similar manner to the systems previously known, previously described with reference to FIGS. 1 and 5.

Le signal de déclenchement issu de la porte 714 est alors appliqué à l'entrée du module pilote 420, de sorte que chaque signal de déclenchement initie un cycle de remise à zéro ou "lavage" du CCD, d'intégration de l'image sur le CCD, puis de lecture de celui-ci par l'intermédiaire du module 430.The trigger signal from gate 714 is then applied to the input of the pilot module 420, so that each trigger signal initiates a reset or "wash" cycle of the CCD, of integration of the image on the CCD, then read it via the module 430.

Les signaux ainsi obtenus transitent ensuite par une carte d'interface 720 avant d'être dirigés vers l'ordinateur 500 ou ils sont traités de façon connue en soi, comme décrit dans les documents antérieurs précédemment décrits.The signals thus obtained then pass through an interface card 720 before being directed to the computer 500 or they are processed in a manner known per se, as described in the prior documents previously described.

On notera que l'écran de phosphore 340 doit présenter une période compatible avec la durée de remise à zéro du CCD 410. En effet, cet écran doit mémoriser l'image durant la remise à zéro du CCD qui précède chaque intégration.Note that the phosphor screen 340 must have a period compatible with the duration of resetting the CCD 410. This screen must memorize the image during the resetting of the CCD which precedes each integration.

Pour obtenir une durée de remise à zéro très courte, par exemple de l'ordre de 1 µs, on peut utiliser un système anti-éblouissement de certains CCD conforme aux dispositions décrites dans le document "The UA2 scintillating fiber detector" R.E. Ansorge et al, Nuclear Instrument and Methods A 273 (1988) 748-753. Le temps d'intégration peut alors être réduit en proportion, grâce à l'emploi d'un écran de phosphore semi-rapide (quelques µs). Ce type de fonctionnement rend négligeable la contribution du bruit de fond thermique du détecteur.To obtain a very short reset time, for example of the order of 1 μs, it is possible to use an anti-glare system for certain CCDs in accordance with the provisions described in the document "The UA2 scintillating fiber detector" RE Ansorge et al , Nuclear Instrument and Methods A 273 (1988) 748-753. The integration time can then be reduced in proportion, thanks to the use of a semi-fast phosphor screen (a few µs). This type of operation makes the contribution of the thermal background noise of the detector negligible.

L'imageur conforme à la présente invention permet de réaliser une image d'une source lumineuse très faible (sensibilité au photoélectron unique) avec une résolution de l'ordre de 20 µm.The imager according to the present invention makes it possible to produce an image of a very weak light source (sensitivity to the single photoelectron) with a resolution of the order of 20 μm.

Rappelons qu'un dispositif à transfert de charges (CCD) est un réseau matriciel d'environ 10⁴ cellules photosensibles de petites tailles (environ 20x20 µm) aptes à transformer chacune un photon reçu en électron. Chaque cellule accumule durant la phase d'intégration, une quantité de charges proportionnelle à l'éclairement qu'elle reçoit. L'étape de lecture consiste à transférer séquentiellement le contenu de chaque cellule vers un dispositif d'imagerie (en l'espèce de préférence l'ordinateur 500, via la carte d'interface 720).Recall that a charge transfer device (CCD) is a matrix network of around 10⁴ small photosensitive cells (around 20x20 µm) capable of transforming each received photon into electron. Each cell accumulates during the integration phase, a quantity of charges proportional to the illumination it receives. The stage reading consists in sequentially transferring the content of each cell to an imaging device (in this case preferably the computer 500, via the interface card 720).

Le cas échéant, dans le cadre de la présente invention, le dispositif à transfert de charges 410 peut être remplacé par un dispositif de type CID connu de l'homme de l'art dans lequel les charges accumulées dans chaque cellule sont lues directement sans transfert.Where appropriate, in the context of the present invention, the charge transfer device 410 can be replaced by a CID type device known to those skilled in the art in which the charges accumulated in each cell are read directly without transfer .

Les inventeurs ont réalisé notamment des essais à l'aide d'un imageur comprenant un tube 300 amplificateur de lumière à focalisation de proximité équipé d'une double galette à microcanaux 330, 331 pour obtenir un gain électron/électron de l'ordre de 10⁵ et d'un écran de phosphore rapide (P47), une caméra électronique 400 à CCD, un amplificateur de tension 710 bas bruit (< 5 mV) large bande passante (de l'ordre de 200 MHz) ayant un gain en tension de 100, et une porte linéaire intégratrice 714 commercialisée par la Société SEPH.The inventors notably carried out tests using an imager comprising a tube 300 light amplifier with proximity focusing equipped with a double microchannel wafer 330, 331 to obtain an electron / electron gain of the order of 10⁵ and a fast phosphor screen (P47), a 400 CCD electronic camera, a low noise (<5 mV) wide bandwidth 710 voltage amplifier (of the order of 200 MHz) having a voltage gain of 100 , and an integrating linear door 714 sold by the company SEPH.

Ces essais ont révélé une efficacité de déclenchement de 90 % sur des évènements lumineux incidents d'amplitude minimale, correspondant à un photo-électron unique. Cette efficacité correspond au rapport entre le nombre de mono-photons électrons émis par la photocathode du tube 300 et le nombre de ceux réellement détectés par le système imageur.These tests revealed a triggering efficiency of 90% on incident light events of minimum amplitude, corresponding to a single photo-electron. This efficiency corresponds to the ratio between the number of electron mono-photons emitted by the photocathode of the tube 300 and the number of those actually detected by the imaging system.

L'imageur précédemment décrit est conçu pour détecter des photons lumineux incidents.The imager previously described is designed to detect incident light photons.

L'imageur peut cependant aisément être adapté pour détecter d'autres types de rayons incidents, tels que par exemple des rayons β ⁻ en plaçant un système convertisseur de ces rayons incidents en lumière, tel qu'un scintillateur 200, en amont du tube 300, comme représenté en traits interrompus sur la figure 7.The imager can however easily be adapted to detect other types of incident rays, such as for example β ⁻ rays by placing a system for converting these incident rays into light, such as a scintillator 200, upstream of the tube 300 , as shown in broken lines in Figure 7.

Bien entendu, la présente invention n'est pas limitée aux modes de réalisation qui viennent d'être décrits, mais s'étend à toutes variantes conformes aux revendications.Of course, the present invention is not limited to the embodiments which have just been described, but extends to all variants according to the claims.

Le cas échéant, on peut par exemple envisager d'utiliser un tube à galette à microcanaux unique.If necessary, one can for example consider using a single microchannel pancake tube.

De même, on peut envisager d'utiliser un tube amplificateur de lumière à focalisation électrostatique comme représenté schématiquement sur les figures 1 et 5.Likewise, it is possible to envisage using a light amplifier tube with electrostatic focusing as shown diagrammatically in FIGS. 1 and 5.

Claims (12)

  1. A low light level, high resolution imager of the type comprising:
       a light-amplifying tube (300) comprising:
          a photocathode (310);
          at least one microchannel slab (330, 331) serving as an electron amplifier; and
          a light emitting phosphor screen (340) provided with a metal layer (342);
       an electron camera (400) comprising a photosensitive matrix array (410) suitable for transforming a received photon into an electron; and
       control means (700) for controlling the electron camera (400);
       the imager being characterized by the fact that the control means (700) comprise an amplifier (710) responsive to the electrons collected on the metal layer (342) of the light-emitting phosphor screen (340) to control integration cycles of the photosensitive matrix array (410) in repetitive one-shot mode synchronized on the appearance of photons at the inlet to the light-amplifying tube (300).
  2. An imager according to claim 1, characterized by the fact that the light-amplifying tube (300) includes two microchannel slabs (330, 331).
  3. An imager according to claim 1 or 2, characterized by the fact that the electron/electron gain of the light-amplifying tube (300) is of the order of 10⁵.
  4. An imager according to any one of claims 1 to 3, characterized by the fact that the photosensitive matrix array (410) of the electron camera (400) is a charge coupled device.
  5. An imager according to any one of claims 1 to 4, characterized by the fact that the metal layer (342) of the phosphor screen (340) is grounded via a resistor (R712) and is also connected to the input of the control amplifier (710).
  6. An imager according to any one of claims 1 to 5, characterized by the fact that a logic shaping gate (714) is interposed between the output of the control amplifier (710) and the electron camera (400).
  7. An imager according to any one of claims 1 to 6, characterized by the fact that a system (200) suitable for transforming incident radiation into light is placed upstream from the light-amplifying tube (300).
  8. An imager according to claim 7, characterized by the fact that a scintillator (200) is placed upstream from the light-amplifying tube (300).
  9. An imager according to any one of claims 1 to 8, characterized by the fact that the light-amplifying tube (300) is a proximity focusing tube.
  10. An imager according to any one of claims 1 to 8, characterized by the fact that the light-amplifying tube (300) is a tube with electrostatic focusing.
  11. An imager according to any one of claims 1 to 10, characterized by the fact that the metal layer (342) of the light-amplifying tube (300) is based on aluminum.
  12. An imager according to claim 1, characterized by the fact that the photosensitive matrix array (410) is of the CID type.
EP91914906A 1990-08-23 1991-08-21 Low light level, high resolution imager Expired - Lifetime EP0544739B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9010593A FR2666170B1 (en) 1990-08-23 1990-08-23 HIGH RESOLUTION IMAGER AT LOW LIGHT LEVEL.
FR9010593 1990-08-23
PCT/FR1991/000680 WO1992003836A1 (en) 1990-08-23 1991-08-21 Low light level, high resolution imager

Publications (2)

Publication Number Publication Date
EP0544739A1 EP0544739A1 (en) 1993-06-09
EP0544739B1 true EP0544739B1 (en) 1994-12-14

Family

ID=9399809

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91914906A Expired - Lifetime EP0544739B1 (en) 1990-08-23 1991-08-21 Low light level, high resolution imager

Country Status (7)

Country Link
US (1) US5294788A (en)
EP (1) EP0544739B1 (en)
JP (1) JP3141205B2 (en)
AT (1) ATE115769T1 (en)
DE (1) DE69105983T2 (en)
FR (1) FR2666170B1 (en)
WO (1) WO1992003836A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2706635B1 (en) * 1993-06-11 1995-07-21 Eprest Night vision binoculars with electronic imagery.
US9273548B2 (en) 2012-10-10 2016-03-01 Halliburton Energy Services, Inc. Fiberoptic systems and methods detecting EM signals via resistive heating
US9091785B2 (en) 2013-01-08 2015-07-28 Halliburton Energy Services, Inc. Fiberoptic systems and methods for formation monitoring
US9513398B2 (en) 2013-11-18 2016-12-06 Halliburton Energy Services, Inc. Casing mounted EM transducers having a soft magnetic layer
WO2016085511A1 (en) 2014-11-26 2016-06-02 Halliburton Energy Services, Inc. Onshore electromagnetic reservoir monitoring
US10793772B1 (en) 2020-03-13 2020-10-06 Accelovant Technologies Corporation Monolithic phosphor composite for sensing systems
US11359976B2 (en) 2020-10-23 2022-06-14 Accelovant Technologies Corporation Multipoint surface temperature measurement system and method thereof
US11353369B2 (en) 2020-11-05 2022-06-07 Accelovant Technologies Corporation Optoelectronic transducer module for thermographic temperature measurements

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3742224A (en) * 1972-02-29 1973-06-26 Litton Systems Inc Light amplifier device having an ion and low energy electron trapping means
US3777201A (en) * 1972-12-11 1973-12-04 Litton Systems Inc Light amplifier tube having an ion and low energy electron trapping means
JPS61296289A (en) * 1985-06-25 1986-12-27 Hamamatsu Photonics Kk Apparatus for detecting alpha-ray image
JPS63155534A (en) * 1986-12-18 1988-06-28 Toshiba Corp X-ray fluorescent multiplier
FR2615654B1 (en) * 1987-05-22 1989-07-28 Sodern LINE COMPENSATION IMAGE ANALYZER TUBE
US5235191A (en) * 1992-03-06 1993-08-10 Miller Robert N Real-time x-ray device

Also Published As

Publication number Publication date
FR2666170A1 (en) 1992-02-28
ATE115769T1 (en) 1994-12-15
FR2666170B1 (en) 1992-12-11
EP0544739A1 (en) 1993-06-09
US5294788A (en) 1994-03-15
JPH06500424A (en) 1994-01-13
DE69105983D1 (en) 1995-01-26
WO1992003836A1 (en) 1992-03-05
JP3141205B2 (en) 2001-03-05
DE69105983T2 (en) 1995-07-20

Similar Documents

Publication Publication Date Title
EP0763751B1 (en) Method and apparatus for correcting signals in gamma photon spectroscopy
US20110084212A1 (en) Multi-layer photon counting electronic module
WO2012174940A1 (en) Multi-spectral imaging method for ultraweak photon emission and system thereof
US7157680B2 (en) Photon arrival time detection
EP0544739B1 (en) Low light level, high resolution imager
EP1004040B1 (en) Spectrometry measuring device in the field of photon gamma detection
US20060186363A1 (en) Enhanced spectral range imaging sensor
EP0762145B1 (en) Gamma particle pulse processing system for CdTe radiation detector
EP0352831B1 (en) Television system for producing colour pictures at a low light intensity level
FR3071788A1 (en) DRIVER OBSERVATION SYSTEM AND METHOD OF SEIZING IT BY THE SYSTEM AND METHOD FOR MANUFACTURING THE SYSTEM
EP0593333B1 (en) Detector cell, detector, sensor for spectroscope
US8421016B2 (en) Laser-pulse matrix detector with rapid summation
EP2037241B1 (en) Device for detecting electromagnetic radiation with current limit
WO1998053339A1 (en) Device for measuring exposure of a solid state image sensor subjected to an ionising radiation and detector equipped with same
US5294789A (en) Gamma-insensitive optical sensor
Bosch Dynamic uses of image intensifiers
Opal et al. Evaluation of large format electron bombarded virtual phase CCDs as ultraviolet imaging detectors
Jerram et al. Electron multiplying ccds
FR2690785A1 (en) Device for the two-dimensional detection and localization of particles.
Mirzoyan et al. A CCD-Based Atmospheric Imaging Detector for SHE-UHE-EHE Astroparticle Physics
WO2019121528A1 (en) Method and system for imaging at high and low light levels
CA2203413A1 (en) Dispositif de detection de rayons x a base de semi-conducteurs
Bailey Response of the upper atmosphere to variations in the solar soft x-ray irradiance. Ph. D. Thesis
FR2906076A1 (en) Luminous image intensifier`s sensitivity control device, has processing unit associated to capturing zones of retina, and multilayer deposit with sectors electrically polarized by polarizing source based on lighting level detected by retina
JPH06290714A (en) X-ray image pick-up tube

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19930301

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE

17Q First examination report despatched

Effective date: 19940128

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19941214

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19941214

Ref country code: DK

Effective date: 19941214

Ref country code: NL

Effective date: 19941214

Ref country code: AT

Effective date: 19941214

REF Corresponds to:

Ref document number: 115769

Country of ref document: AT

Date of ref document: 19941215

Kind code of ref document: T

REF Corresponds to:

Ref document number: 69105983

Country of ref document: DE

Date of ref document: 19950126

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19950110

ITF It: translation for a ep patent filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19950314

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19950831

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19950831

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
BERE Be: lapsed

Owner name: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS

Effective date: 19950831

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20100723

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20100727

Year of fee payment: 20

Ref country code: DE

Payment date: 20100806

Year of fee payment: 20

Ref country code: FR

Payment date: 20100910

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20100727

Year of fee payment: 20

REG Reference to a national code

Ref country code: CH

Ref legal event code: PFA

Owner name: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (CNR

Free format text: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (CNRS)#15, QUAI ANATOLE FRANCE#PARIS 7E (FR) -TRANSFER TO- CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (CNRS)#15, QUAI ANATOLE FRANCE#PARIS 7E (FR)

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69105983

Country of ref document: DE

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69105983

Country of ref document: DE

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20110820

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20110822