EP0588432A1 - Appareil à rayons X avec un générateur à rayons X et un tube radiogène avec au moins deux sources d'électrons - Google Patents

Appareil à rayons X avec un générateur à rayons X et un tube radiogène avec au moins deux sources d'électrons Download PDF

Info

Publication number
EP0588432A1
EP0588432A1 EP93202650A EP93202650A EP0588432A1 EP 0588432 A1 EP0588432 A1 EP 0588432A1 EP 93202650 A EP93202650 A EP 93202650A EP 93202650 A EP93202650 A EP 93202650A EP 0588432 A1 EP0588432 A1 EP 0588432A1
Authority
EP
European Patent Office
Prior art keywords
ray
control
electron
focal spot
electron source
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.)
Granted
Application number
EP93202650A
Other languages
German (de)
English (en)
Other versions
EP0588432B1 (fr
Inventor
Franz Dr. Rer. Nat. Buchmann
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.)
Philips Intellectual Property and Standards GmbH
Koninklijke Philips NV
Original Assignee
Philips Patentverwaltung GmbH
Koninklijke Philips Electronics NV
Philips Electronics NV
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 Philips Patentverwaltung GmbH, Koninklijke Philips Electronics NV, Philips Electronics NV filed Critical Philips Patentverwaltung GmbH
Publication of EP0588432A1 publication Critical patent/EP0588432A1/fr
Application granted granted Critical
Publication of EP0588432B1 publication Critical patent/EP0588432B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/52—Target size or shape; Direction of electron beam, e.g. in tubes with one anode and more than one cathode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/045—Electrodes for controlling the current of the cathode ray, e.g. control grids
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/46—Combined control of different quantities, e.g. exposure time as well as voltage or current
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2235/00—X-ray tubes
    • H01J2235/06—Cathode assembly
    • H01J2235/068—Multi-cathode assembly

Definitions

  • the invention relates to an X-ray generator for supplying an X-ray tube, which has at least two electron sources for producing focal spots of different sizes at the same location on the anode.
  • X-ray tubes that can produce two (or more) focal spots at the same location on the anode are known (DE-OS 28 50 583).
  • the known x-ray generators for feeding such x-ray tubes allow the generation of x-rays with either a smaller or a larger focal spot.
  • X-rays with the smaller focal spot have a better resolution
  • X-rays with the larger focal spot have shorter exposure times because the larger focal spot is more resilient and therefore generates more X-rays.
  • the user In the case of an x-ray, the user must therefore decide which of the two focal spots he wants to use.
  • the object of the present invention is to design an x-ray generator for an x-ray tube of the type mentioned at the outset in such a way that the resolving power on the one hand and the power of the x-ray tube on the other hand can be adapted to the respective requirements using simple means - regardless of the voltage of the x-ray tube.
  • each electron source is assigned a control unit, which causes a current dependent on a control signal at a control input of the control unit between the associated electron source and the anode, that both control units are effective and can be controlled independently of one another during an X-ray exposure and that the control signals and thus the ratio between the mAs products supplied by the electron sources can be set.
  • the invention is based on the knowledge that not only the dimensions of the focal spot in which the x-ray radiation is emitted are decisive for the resolving power of an x-ray tube, but also to a considerable extent the spatial distribution of the radiation or emission density in the effective focal spot. It can be shown that an increase in the radiation intensity or the electron density in a small partial area of the focal spot leads to an increase in the resolving power in the image, in particular if this partial area lies in the center of the focal spot. This means that an X-ray image generated with such an electron density distribution in the focal spot has a modulation transfer function that corresponds to that of an X-ray image that was made with a focal spot with a homogeneous electron distribution and with smaller external dimensions.
  • the electron sources are operated by the control units controlling them in such a way that the different focal spots become effective in an X-ray exposure with different weights, depending on the mAs product (below this, the time integral over that flowing from the electron source to the anode during an X-ray exposure Understood electricity) with which they contribute to the recording.
  • This different weighting of the focal spots means that x-ray images can be produced which correspond to the images of an x-ray tube with regard to tube power and modulation transfer function, the focal spot (with uniform electron distribution) in its outer dimensions can be changed in the area between the small and the large focal spot.
  • both filaments can deliver an emission current at the same time.
  • the resolving power of this focal spot combination can be better than that of the large focal spot, and one could not use this effect to vary the resolving power and the power, because the ratio of the emission currents is determined by the supply voltage for the filaments the filaments (and thus the resolution) and the sum of the emission currents (and thus the power) were determined.
  • US Pat. No. 4,065,689 discloses an X-ray generator for feeding an X-ray tube with two focal spots of the same size, which partially overlap.
  • the emission currents for the two focal spots are adjustable. This is to achieve an intensity characteristic which is considered to be particularly favorable there, namely an essentially uniform intensity in the focal spot.
  • the ratio between the mAs products provided by the electron sources i.e. the weight with which the focal spots are effective in an X-ray exposure
  • the control units are active simultaneously during an X-ray exposure.
  • the two electron sources simultaneously supply a constant current during the X-ray exposure.
  • the control units are effective one after the other during a recording. If the control unit can control the electron sources sufficiently quickly (e.g. by means of a grid), a single control unit that controls the electron sources in succession during a recording would suffice.
  • a preferred development of the invention provides that a memory is provided in which different combinations of control signals for the control units are stored for X-ray recordings with different recording parameters, and that the combination of the control signals assigned to the respectively predefined recording parameters is called up for an X-ray recording. This makes it possible to always control the electron sources in the case of X-ray recordings with recording parameters that can be predetermined in any way by the control units in such a way that the optimum combination of the modulation transfer function and the tube power results.
  • the drawing shows a high-voltage generator 2 which feeds an X-ray tube 1 and which, in the case of an X-ray image, supplies a positive high voltage for the anode 10 and a negative high voltage for the cathode (in each case based on ground).
  • the high voltage generated by the high voltage generator 2 can be set by a signal U at its control input.
  • the cathode comprises two electron sources 11 and 12, for example two filaments, which emit an electron current when they are each heated by a heating current.
  • the electron currents supplied by the electron sources strike a specific area of the anode 10 and thereby define a focal spot in each case.
  • the focal spots are arranged concentrically to one another, i.e. the small focal spot that may be generated by the electron source 12 lies in the middle of the large focal spot (from the electron source 11).
  • the focal spots - viewed from the direction of radiation exit, which is symbolized by the dashed arrow 13 - are square.
  • X-ray tubes of this type are generally known and e.g. described in DE-OS 28 50 583.
  • the focal spot generated by the electron source 11 is a 1.1 mm focal spot (ie, it has dimensions of 1.1 mm * 1.1 mm as viewed from the beam exit direction) and that the small focal spot is a 0 , 4mm focal spot.
  • the ratio of the focal spot sizes should not be significantly larger, because otherwise the modulation transfer function can be influenced relatively little by the weighting of the focal spots.
  • the maximum permissible value of the electron current supplied by the electron source 11 can be 1000 mA and the current supplied by the electron source 12 can be 230 mA at a tube voltage of 80 kV.
  • the electron source 12 can deliver its maximum current of 230 mA.
  • the resolution then naturally corresponds to the resolution of the small focal spot, i.e. a 0.4 mm focal spot with a uniform electron density.
  • the tube power is approximately 18.4 kW.
  • the electron current supplied by the electron source 11 is 10% of the maximum permissible value, i.e. 100 mA
  • the electron current supplied by the electron source 12 must be reduced slightly so that the anode is not overheated - for example to 200 mA.
  • the superimposed focal spot formed in this way has the outer dimensions of the large focal spot (1.1 mm), it has a modulation transfer function which corresponds approximately to that of a 0.5 mm focal spot with a uniform electron density.
  • the effective size (based on the modulation transfer function) of the superimposed focal spot would therefore be 0.5 mm.
  • the tube power is then about 26 kW.
  • the current supplied by the electron source 11 is increased to 300 mA, the current supplied by the electron source 12 must be reduced further in order to avoid overloading the anode, for example to 175 mA.
  • the modulation transfer function of this focal spot with an increased electron density in the center then corresponds to that of a 0.6 mm focal spot with a uniform electron density.
  • the tube power is 38 kW.
  • a further increase in the current from the electron source 11 to 500 mA with a simultaneous decrease in the current from the electron source 12 to 125 mA leads to a focal spot whose modulation transfer function corresponds to that of a 0.8 mm focal spot with a homogeneous electron distribution.
  • the tube power is then - at the tube voltage of 80 kV mentioned - already 50 kW.
  • the currents supplied by the electron sources must be lower or higher depending on the load capacity of the X-ray tube.
  • Tube voltages eg 40 kV
  • the heating currents which determine the temperature of the electron sources 11 and 12 and thus the currents emitted by them, are supplied by a control unit 21 and 22, respectively.
  • These control units each include (not shown in detail) a heating current transformer, the primary and secondary windings of which are insulated from one another in such a way that the primary winding can carry ground potential, while the secondary winding is at a negative high voltage.
  • the control units each comprise a control circuit which has the effect that the heating current which the control unit 21 or 22 supplies for the electron source 11 or 12 is proportional to the control signal I h1 or I h2 at the control input of this unit.
  • the control signals I h1 and I h2 thus also determine the electron current between the electron sources 11 and 12 on the one hand and the anode 10 on the other.
  • the control signals I h1 and I h2 are supplied to the control units 21 and 22 via a digital-to-analog converter 31 and 32, respectively.
  • the inputs of these analog-digital converters are connected to a memory unit 4, from which the control signals I h1 and I h2 (in digital form) are read out as a function of predetermined parameters of the X-ray image.
  • the storage unit 4 comprises a storage area 41 and 42 for each electron source 11 or 12. In each of these storage areas, the control signals I h1 and I h2 are stored for different voltages on the X-ray tube which - as explained above for a tube voltage of 80 kV - lead to different currents from the electron sources.
  • the addresses under which the control signals are stored are supplied by an address generator 50, which can be part of a computer system (5) with which all other functions of the X-ray generator are also controlled.
  • the tube power has the greatest value with which the x-ray tube 1 can be operated for the given modulation transfer function.
  • another recording parameter can also be specified, for example the geometric blur, which depends not only on the size f of the focal spot but also on the distances between the X-ray source and the film and between the X-ray source and the object to be recorded. If necessary, the latter two quantities can be recorded by a separate measuring device.
  • the tube voltage is 80 kV
  • the permissible recording time is 100 ms
  • the mAs product is 62.5 mAs
  • a current of 625 mA is calculated for the permissible recording time, which is 125 mA from the electron source 12 and 500 mA the electron source 11 results.
  • the resulting image then has a modulation transfer function which corresponds to that of an X-ray image with a 0.8 mm focal spot with a uniform electron distribution.
  • - X-rays obtained with this assignment thus have the best possible resolution with a tube power that is just sufficient to carry out an X-ray with the intended recording parameters within the specified permissible recording time.
  • the X-ray tube instead of operating the X-ray tube with a constant ratio for a recording between currents supplied by the electron sources 11 and 12, it is also possible to vary these currents during a recording in such a way that the current of the electron source (12), the is assigned to the smaller focal spot, decreases in time from a maximum value, while the current supplied by the other electron source (11) increases - at least within certain time limits - so that with a short exposure time the X-ray image has a higher resolution than with a longer exposure time .
  • the required time profiles of the two control signals could then be stored in the memory areas 41 and 42 as a sequence of digital data words. This would result in the best possible resolution with the respective recording parameters.
  • control units 21 and 22 control the electron sources 11 and 12 by varying their heating currents.
  • the heating currents of the electron sources can be kept constant and instead the grating biases can be varied as desired.
  • the difference between the resulting modulation transfer function and the modulation transfer function of the large focal spot is no longer significant if the current supplied by the electron source 11 is above 500 mA, ie around 50% of the maximum current of this electron source that a continuous variation is only possible in the range from 0 to 50% of the maximum current.
  • the modulation transfer function is to be varied over a wide range, it is expedient to use a further electron source whose focal spot is larger than the small and smaller than the large focal spot. If one then controls the further electron source accordingly instead of the electron source for the small focal spot, a variation in an even larger area of the modulation transfer function is possible.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • X-Ray Techniques (AREA)
EP93202650A 1992-09-16 1993-09-14 Appareil à rayons X avec un générateur à rayons X et un tube radiogène avec au moins deux sources d'électrons Expired - Lifetime EP0588432B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4230880 1992-09-16
DE4230880A DE4230880A1 (de) 1992-09-16 1992-09-16 Röntgengenerator zur Speisung einer Röntgenröhre mit wenigstens zwei Elektronenquellen

Publications (2)

Publication Number Publication Date
EP0588432A1 true EP0588432A1 (fr) 1994-03-23
EP0588432B1 EP0588432B1 (fr) 1996-12-11

Family

ID=6468023

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93202650A Expired - Lifetime EP0588432B1 (fr) 1992-09-16 1993-09-14 Appareil à rayons X avec un générateur à rayons X et un tube radiogène avec au moins deux sources d'électrons

Country Status (4)

Country Link
US (1) US6104781A (fr)
EP (1) EP0588432B1 (fr)
JP (1) JP3506465B2 (fr)
DE (2) DE4230880A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010146504A1 (fr) * 2009-06-17 2010-12-23 Philips Intellectual Property & Standards Gmbh Tube à rayons x pour générer deux points focaux et dispositif médical le comprenant

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19504305A1 (de) * 1995-02-09 1996-08-14 Siemens Ag Röntgenröhre
US7120222B2 (en) * 2003-06-05 2006-10-10 General Electric Company CT imaging system with multiple peak x-ray source
US6980623B2 (en) * 2003-10-29 2005-12-27 Ge Medical Systems Global Technology Company Llc Method and apparatus for z-axis tracking and collimation
US7409043B2 (en) * 2006-05-23 2008-08-05 General Electric Company Method and apparatus to control radiation tube focal spot size
JP5395320B2 (ja) * 2006-08-07 2014-01-22 株式会社東芝 Ｘ線管装置
US9324536B2 (en) * 2011-09-30 2016-04-26 Varian Medical Systems, Inc. Dual-energy X-ray tubes
US10702234B2 (en) 2017-02-22 2020-07-07 Canon Medical Systems Corporation Image combining using images with different focal-spot sizes

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1021512B (de) * 1953-07-15 1957-12-27 Siemens Reiniger Werke Ag Einrichtung zur Einstellung des Heizstromes bei einem Roentgenapparat mit mehreren wahlweise abwechselnd einschaltbaren Roentgenroehren-Gluehkathoden
FR2395669A1 (fr) * 1977-06-23 1979-01-19 Gen Electric Systeme de diagnostic pour rayons x programme sur base de l'anatomie
GB2060959A (en) * 1979-10-04 1981-05-07 Picker Corp X-ray tube current control
FR2491282A1 (fr) * 1980-09-29 1982-04-02 Gen Electric Systeme de fourniture de tension de polarisation pour un tube a rayons x
US4685118A (en) * 1983-11-10 1987-08-04 Picker International, Inc. X-ray tube electron beam switching and biasing method and apparatus
US4823371A (en) * 1987-08-24 1989-04-18 Grady John K X-ray tube system
EP0346530A1 (fr) * 1988-06-16 1989-12-20 Nicola Elias Yanaki Procédé et dispositif pour optimiser la qualité radiographique par contrôle de la tension, du courant, de la dimension du foyer et du temps d'exposition d'un tube à rayons X

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2160605A (en) * 1936-12-18 1939-05-30 Gen Electric Regulating system
US3783333A (en) * 1972-02-24 1974-01-01 Picker Corp X-ray tube with improved control electrode arrangement
US3882339A (en) * 1974-06-17 1975-05-06 Gen Electric Gridded X-ray tube gun
US4065689A (en) * 1974-11-29 1977-12-27 Picker Corporation Dual filament X-ray tube
DE2850583A1 (de) * 1978-11-22 1980-06-04 Philips Patentverwaltung Roentgenroehre mit zwei parallel nebeneinander angeordneten heizfaeden
JPH0673291B2 (ja) * 1988-04-16 1994-09-14 株式会社東芝 Ｘ線管
US5200985A (en) * 1992-01-06 1993-04-06 Picker International, Inc. X-ray tube with capacitively coupled filament drive
US5303281A (en) * 1992-07-09 1994-04-12 Varian Associates, Inc. Mammography method and improved mammography X-ray tube

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1021512B (de) * 1953-07-15 1957-12-27 Siemens Reiniger Werke Ag Einrichtung zur Einstellung des Heizstromes bei einem Roentgenapparat mit mehreren wahlweise abwechselnd einschaltbaren Roentgenroehren-Gluehkathoden
FR2395669A1 (fr) * 1977-06-23 1979-01-19 Gen Electric Systeme de diagnostic pour rayons x programme sur base de l'anatomie
GB2060959A (en) * 1979-10-04 1981-05-07 Picker Corp X-ray tube current control
FR2491282A1 (fr) * 1980-09-29 1982-04-02 Gen Electric Systeme de fourniture de tension de polarisation pour un tube a rayons x
US4685118A (en) * 1983-11-10 1987-08-04 Picker International, Inc. X-ray tube electron beam switching and biasing method and apparatus
US4823371A (en) * 1987-08-24 1989-04-18 Grady John K X-ray tube system
EP0346530A1 (fr) * 1988-06-16 1989-12-20 Nicola Elias Yanaki Procédé et dispositif pour optimiser la qualité radiographique par contrôle de la tension, du courant, de la dimension du foyer et du temps d'exposition d'un tube à rayons X

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010146504A1 (fr) * 2009-06-17 2010-12-23 Philips Intellectual Property & Standards Gmbh Tube à rayons x pour générer deux points focaux et dispositif médical le comprenant
US9142381B2 (en) 2009-06-17 2015-09-22 Koninklijke Philips N.V. X-ray tube for generating two focal spots and medical device comprising same

Also Published As

Publication number Publication date
EP0588432B1 (fr) 1996-12-11
JPH06196293A (ja) 1994-07-15
DE59304733D1 (de) 1997-01-23
JP3506465B2 (ja) 2004-03-15
US6104781A (en) 2000-08-15
DE4230880A1 (de) 1994-03-17

Similar Documents

Publication Publication Date Title
DE69022500T2 (de) Stromregelung für Röntgenröhren mit konstanter Schleifenverstärkung.
DE3783170T2 (de) Schaltungsanordnung zur erzeugung von hochspannungen.
DE2841102C2 (fr)
DE69104279T2 (de) Automatische Kalibrierungsvorrichtung.
EP0588432B1 (fr) Appareil à rayons X avec un générateur à rayons X et un tube radiogène avec au moins deux sources d'électrons
DE2917636A1 (de) Roentgengenerator
DE3037533A1 (de) Schaltungsanordnung zur regelung des ausgangsstromes einer roentgenroehre
DE2332118A1 (de) Verfahren und vorrichtung zur minimisierung der querkomponenten der geschwindigkeit in einem elektronenstrahl
DE2747441B2 (de) Als Einzellinse ausgebildete Fokussierlinse in einem Elektronenstrahlerzeugersystem
EP0253417B1 (fr) Générateur de rayons X
EP0036181B1 (fr) Appareil de diagnostic par rayons X comportant une chaîne de télévision à intensificateur d'images
DE2325808C2 (de) Schaltung zur Regelung der Betriebsparameter eines Elektronenstrahlerzeugers
DE3600205C2 (fr)
DE2542016A1 (de) Schaltungsanordnung zur einstellung des aufnahmestroms einer roentgenroehre
DE10136947A1 (de) Röntgensystem zur Erzeugung von Röntgenaufnahmen
DE69018155T2 (de) Apparat und Verfahren für Röntgenaufnahmen.
DE2924682A1 (de) Speiseanordnung
DE3043632A1 (de) Roentgengenerator zur speisung einer roentgenroehre mit einem zwischen ihrer anode und ihrer kathode befindlichen mit masse verbundenen mittelteil
EP0270920A2 (fr) Procédé et dispositif de production de signaux de courant d'émission dans un réseau de distribution d'énergie à courant alternatif
DE3010978C2 (de) Schaltungsanordnung zur Beseitigung der Spur eines Spitzlichtes bei der Aufnahme eines Bildes mit einer Fernsehaufnahmeröhre
DE3151203C2 (fr)
DE904779C (de) Verfahren zur Hochspannungserzeugung fuer Braunsche Roehren, insbesondere bei Fernsehuebertragungen
DE2332604A1 (de) Vorrichtung zur konstanthaltung des von einer elektronenquelle erzeugten elektronenstroms
DE971521C (de) Einrichtung zur Erzeugung von zwei miteinander in einem festen Zusammenhang stehenden, bezueglich eines gemeinsamen Erdpunktes gegenpoligen hohen Gleichspannungen
DE2443478C3 (de) Schaltungsanordnung zur Verzögerung des Aufbaus einer Zusatzspannung, die zur Betriebsspannung eines Fernsehempfängers hinzuaddiert wird

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

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: N.V. PHILIPS' GLOEILAMPENFABRIEKEN

Owner name: PHILIPS PATENTVERWALTUNG GMBH

17P Request for examination filed

Effective date: 19940908

17Q First examination report despatched

Effective date: 19950721

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 59304733

Country of ref document: DE

Date of ref document: 19970123

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

Effective date: 19970225

ET Fr: translation filed
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
REG Reference to a national code

Ref country code: FR

Ref legal event code: CD

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

REG Reference to a national code

Ref country code: GB

Ref legal event code: 746

Effective date: 20020906

REG Reference to a national code

Ref country code: FR

Ref legal event code: D6

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

Ref country code: GB

Payment date: 20030930

Year of fee payment: 11

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 NON-PAYMENT OF DUE FEES

Effective date: 20040914

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20040914

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

Ref country code: DE

Payment date: 20101129

Year of fee payment: 18

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

Ref country code: FR

Payment date: 20111012

Year of fee payment: 19

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20130531

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 59304733

Country of ref document: DE

Effective date: 20130403

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 NON-PAYMENT OF DUE FEES

Effective date: 20130403

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

Ref country code: FR

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

Effective date: 20121001