EP0089016A1 - Procédé pour le réglage automatique des couleurs imprimées par les machines d'impression flexographiques imprimant en quatre couleurs - Google Patents

Procédé pour le réglage automatique des couleurs imprimées par les machines d'impression flexographiques imprimant en quatre couleurs Download PDF

Info

Publication number
EP0089016A1
EP0089016A1 EP83102351A EP83102351A EP0089016A1 EP 0089016 A1 EP0089016 A1 EP 0089016A1 EP 83102351 A EP83102351 A EP 83102351A EP 83102351 A EP83102351 A EP 83102351A EP 0089016 A1 EP0089016 A1 EP 0089016A1
Authority
EP
European Patent Office
Prior art keywords
color
determined
printing
triangle
printed
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
EP83102351A
Other languages
German (de)
English (en)
Other versions
EP0089016B1 (fr
Inventor
Klaus P. Dr. Dotzel
Heinz Eschmeier
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.)
Windmoeller and Hoelscher KG
Original Assignee
Windmoeller and Hoelscher KG
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 Windmoeller and Hoelscher KG filed Critical Windmoeller and Hoelscher KG
Publication of EP0089016A1 publication Critical patent/EP0089016A1/fr
Application granted granted Critical
Publication of EP0089016B1 publication Critical patent/EP0089016B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41F—PRINTING MACHINES OR PRESSES
    • B41F5/00—Rotary letterpress machines
    • B41F5/24—Rotary letterpress machines for flexographic printing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41F—PRINTING MACHINES OR PRESSES
    • B41F33/00—Indicating, counting, warning, control or safety devices
    • B41F33/0036—Devices for scanning or checking the printed matter for quality control
    • B41F33/0045—Devices for scanning or checking the printed matter for quality control for automatically regulating the ink supply

Definitions

  • the invention relates to a method for the automatic setting of the colors printed by flexographic printing presses with printing plate cylinders with printing plate and impression cylinders for four-color printing with the printing colors yellow, magenta, cyan and black.
  • the object of the invention is therefore to provide a method by which the printed colors can be automatically adjusted correctly without changing the color tone and / or the color strength of the individual printing inks.
  • this object is achieved in that, in order to determine the color setpoint in a color triangle serving to compare the colors, the corners of which are defined by the printing inks yellow, magenta and cyan, the color location for a screen test field printed out by all printing units, in which each of the printing inks has its own Color portion is involved between about 40 and 60%, it is determined that to determine the actual value of the color based on a densitometric measurement, the actually present portions of the printing inks are measured in the test field and from the measurement of the color location of the actual value in the color triangle It is determined that from the comparison of the color words, the deviations of the actual values of the color components from the nominal values of the color components of each color are determined and that, according to the deviations, the center distance of the plate cylinder of the respective color from the impression cylinder is changed until the actual and the target - Match the value in the color triangle.
  • the correct color tone and the correct color strength of the individual printing inks are set, for example, using the method described in DE-OS 30 07 421.
  • each color box color is measured in a known manner with a densitometer with blue, red and green filters, so that the proportions of the complementary colors in the color box color that correspond to the original result from this measurement.
  • the remission curve with which the measured colors can be clearly determined can be determined from the densitometer measurements by approximate integration.
  • a triangle of a polar coordinate system is formed from the color box colors, in the present case yellow, magenta and cyan, the zero point of which is determined by the achromatic point. From this achromatic point, vectors can be drawn to the degrees of mixing that delimit the triangle, so that the angle of the vector indicates the miscible hue.
  • the length of the vector is a measure of the degree of chromaticity, which can be determined by adding black.
  • the Farbpolygonzug or the color triangle indicates the respective color plane, wherein the color strength is defined arben plane through the length of the perpendicular to the bottom F, the coordinates of zero is white.
  • the coordinate zero point of the top color level is black.
  • the color intensity is determined by the length of the vector, the color tone by the vector angle and the color intensity by the length of the solder to determine the measured color and compared with a predetermined target value.
  • color concentrate or waste is added in the manner specified in DE-OS 30 07 421.
  • the printed colors are set according to the procedure.
  • the color location for the color setpoint is determined in a color triangle, the corners of which are defined by the printing inks yellow, magenta and cyan, which must be shown by a screen test field printed out by all printing units.
  • This color setpoint is expediently set in the color triangle in such a way that each of the printing inks with a color proportion of between about 40 and 60% is involved. The proportion of all printing inks should be large enough to be able to measure sufficiently large values.
  • the actual value of the color in the actually printed raster test field is determined in a known manner by densitometric measurements with red, green and blue filters, so that the color location of the actual value in the previously defined color triangle can be determined from the measurement.
  • the deviations of the actual values of the color components from the nominal values of the color components of each color can be determined.
  • the center distance of the plate cylinder of the respective color from the impression cylinder is then changed in such a way that the actual value and the target value in the color triangle are brought into agreement.
  • the measured actual value of the color can be converted to the setpoint value by rotating rays around the magenta corner point and the cyan corner point of the triangle, starting from the corners in the color triangle Center of gravity, which corresponds to the black point, lines are drawn and the quadrilaterals, which are defined by the triangle lines starting from the corners and the lines which extend beyond the center of gravity, are completely covered by the color determined by the associated triangle corner point, that of for each line of the square within the color triangle assigned to a color, which is formed by the line extended beyond the center of gravity, a decreasing color wedge of the color of the square closed by this line to the opposite.
  • a section of the printed image is selected as the raster test field which corresponds to a selected target value with a color distribution that is as uniform as possible.
  • Such suitable raster test fields can be found in all printed images, so that it is not necessary to provide a separate raster test field, but instead the densitometric measurements for determining the actual value can be carried out directly in the printed image.
  • the corner points of the triangle need not be formed by the basic printing inks, they can also consist of other colors.
  • the color tone achieved on the material to be printed is determined by the coloristic properties of the printing ink and its concentration. Experience has shown that the color tone for highly qualified four-color halftone prints must be in very specific areas. The corresponding hue values and the color strength as well as the degree of color are determined for each of the printing inks yellow, magenta and cyan.
  • the color tone is defined here as the angle of rotation around the gray axis of the color circle, the color strength as total density and the degree of color as the distance of the color tone vector from the black center of the color circle.
  • the color strength value depends on the color concentration.
  • the upward deviation from the target value indicates a higher concentration, which can be compensated for by adding blends. If the color strength is too low, it is corrected by adding concentrate.
  • the concentration of the printing ink is set correctly, the color strength measured in the full-area test field depends on the ink layer thickness. This is determined in the inking unit by the inclusion of the anilox roller on the forme cylinder, so that it is possible to adjust the center distance via the corresponding servomotors after the measured color strength.
  • the density values of the printed colors are measured on a test field printed in three colors in the basic colors with known screen coverings and the actual screen coverings are calculated.
  • the control commands for the servomotors, which set the center distance of the plate and counter-pressure cylinders, result from the difference between the actual and the setpoints.
  • the type of determination of the control commands for the servomotors is explained in more detail below using the color triangle Y-M-C.
  • the color triangle shown is created by printing raster wedges in three colors. The corner colors of the triangle are yellow due to the three basic colors. (Y), magenta (M) and cyan (C).
  • the focus of this triangle S is the full-surface overprinting of the primary colors.
  • magenta is printed over the entire surface and money and cyan are printed with a correspondingly increasing screen wedge.
  • cyan is printed over the entire surface and the other two colors are printed with decreasing or increasing grid wedges.
  • the cyan raster portion is a function of the angle of rotation ⁇ around the magenta point M and the magenta raster portion is a function of the angle of rotation ⁇ about the cyan point C.
  • the situation in the other fields is similar.
  • Each point in the color triangle is thus clearly defined by two angles of rays that can be rotated around the magenta and cyan points.
  • the corresponding grid coverage can be calculated if the functions are determined experimentally.
  • the coordinate system rc shown in the drawing is the same as that used to determine the dimensions for the hue, the color strength and the chromaticity.
  • the grid coverage proportions can thus be determined from the optical densities.
  • composition and measurement result yellow 55%, magenta 52%, cyan 45%.
  • the differences between the target and actual values are measured numbers for the number of pulses for the servomotors.
  • the densitometers are mounted in the printing press in such a way that a number of measuring marks can be scanned during the run.
  • To determine the setting of the ink fountain colors yellow, magenta and cyan are printed out over the entire surface and measured.
  • the densitometer is used to measure the actual value using the grid test field, in which the colors yellow, magenta and cyan are each approximately 40 to 60%.
  • the densities measured by the densitometer behind the three colored filters are then fed to a process computer.
  • the actual values according to hue, color strength and degree of color are measured for the inking units according to the method described in DE-OS 30 07 421 and the corresponding values are obtained from the comparison with the specified target values. Corrections made. ,
  • the corresponding control commands for the servomotors for the adjustment of the plate cylinder to the impression cylinder are determined from the target / actual value comparison of the grid area covers determined from the grid test field.
  • the target values are approximated until the desired print image is achieved after visual assessment.
  • the actual values achieved are determined as target values for the production run.
  • the specified target numbers are continuously monitored automatically during the printing phase. The results can be displayed on a screen. The readjustment can take place automatically as in the setup phase.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Quality & Reliability (AREA)
  • Inking, Control Or Cleaning Of Printing Machines (AREA)
  • Printing Methods (AREA)
EP83102351A 1982-03-16 1983-03-10 Procédé pour le réglage automatique des couleurs imprimées par les machines d'impression flexographiques imprimant en quatre couleurs Expired EP0089016B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3209483 1982-03-16
DE19823209483 DE3209483A1 (de) 1982-03-16 1982-03-16 Verfahren zum automatischen einstellen der von flexodruckmaschinen fuer den vierfarbendruck ausgedrucktenfarben

Publications (2)

Publication Number Publication Date
EP0089016A1 true EP0089016A1 (fr) 1983-09-21
EP0089016B1 EP0089016B1 (fr) 1985-06-05

Family

ID=6158365

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83102351A Expired EP0089016B1 (fr) 1982-03-16 1983-03-10 Procédé pour le réglage automatique des couleurs imprimées par les machines d'impression flexographiques imprimant en quatre couleurs

Country Status (5)

Country Link
US (1) US4667596A (fr)
EP (1) EP0089016B1 (fr)
JP (1) JPS58175687A (fr)
CA (1) CA1199521A (fr)
DE (1) DE3209483A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0196431A2 (fr) * 1985-03-21 1986-10-08 Felix Brunner Procédé, dispositif de réglage et moyens auxiliaires pour l'obtention d'un résultat d'impression uniforme au moyen d'une machine d'impression offset polychrome fonctionnant suivant le procédé de similigravure
EP0228347A1 (fr) * 1985-12-10 1987-07-08 Heidelberger Druckmaschinen Aktiengesellschaft Procédé de commande de l'alimentation en encre pour une machine à imprimer, dispositif d'impression équipé de manière correspondante et dispositif de mesure pour un tel appareil d'impression
EP0282446A1 (fr) * 1987-02-23 1988-09-14 GRETAG Aktiengesellschaft Procédé de réglage continu de l'encrage en impression en creux ou flexographique et machine correspondante
EP0337148A2 (fr) * 1988-04-12 1989-10-18 Heidelberger Druckmaschinen Aktiengesellschaft Procédé de commande de l'encrage d'une machine d'impression
FR2643017A1 (fr) * 1989-02-10 1990-08-17 Heidelberger Druckmasch Ag Procede de reglage de la coloration de produits imprimes
EP0394681A2 (fr) * 1989-04-24 1990-10-31 Heidelberger Druckmaschinen Aktiengesellschaft Procédé pour contrôler l'encrage dans une machine d'impression avec limitation de l'épaisseur de la couche d'encre et de l'augmentation de la valeur tonale
EP1862307A3 (fr) * 2006-06-02 2008-06-04 Heidelberger Druckmaschinen Aktiengesellschaft Procédé destiné au calcul des valeurs de correction dans une commande couleur ou une régulation de couleur pour une presse d'impression
EP1666252A3 (fr) * 2001-03-27 2009-10-21 Windmöller & Hölscher KG Dispositif et procédé de réglage de l'image d'impression dans une machine d'impression flexographique

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5182721A (en) * 1985-12-10 1993-01-26 Heidelberger Druckmaschinen Aktiengesellschaft Process and apparatus for controlling the inking process in a printing machine
DE3714179A1 (de) * 1987-04-29 1988-11-17 Forschungsgesellschaft Fuer Dr Verfahren zur steuerung der farbgebung im mehrfarbendruck
FI78025C (fi) * 1987-08-31 1989-06-12 Valtion Teknillinen Foerfarande foer kvalitetskontroll av tryckning.
US4967379A (en) * 1987-12-16 1990-10-30 Gretag Aktiengesellschaft Process for the ink control or regulation of a printing machine by comparing desired color to obtainable color data
US4975862A (en) * 1988-01-14 1990-12-04 Gretag Aktiengesellschaft Process and apparatus for the ink control of a printing machine
DE4431270C2 (de) * 1993-10-21 1997-01-16 Roland Man Druckmasch Verfahren zur Steuerung der Farbführung einer autotypisch arbeitenden Druckmaschine
DE4413735C2 (de) * 1994-04-20 2003-09-25 Heidelberger Druckmasch Ag Verfahren zum Steuern oder Regeln des Druckprozesses einer autotypisch arbeitenden Druckmaschine beim Drucken unter Druckpressung auf einen Bedruckstoff
US5819655A (en) * 1997-08-20 1998-10-13 Bristol-Myers Squibb Company Cyclinder color printing method and product using improved misregistration detection
US5895836A (en) * 1997-11-06 1999-04-20 Uzik; Barry K. Greyscale calibration method in digital printing
US6774907B1 (en) * 1999-12-17 2004-08-10 Adobe Systems Incorporated Tint transformation of fill
US20040200369A1 (en) * 2003-04-11 2004-10-14 Brady Thomas P. Method and system for printing press image distortion compensation
US9325860B2 (en) 2010-12-01 2016-04-26 Quadtech, Inc. Line color monitoring system
WO2012084452A1 (fr) * 2010-12-23 2012-06-28 Tetra Laval Holdings & Finance S.A. Impression flexographique améliorée, dispositif et procédé
IT1403496B1 (it) 2010-12-27 2013-10-17 Uteco Converting Spa Sistema e procedimento di regolazione e controllo delle pressioni di cilindri di stampa in una macchina da stampa flessografica a tamburo centrale

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2969016A (en) * 1955-03-18 1961-01-24 Crosfield J F Ltd Colour printing
DE2060000A1 (de) * 1970-12-05 1972-06-15 Hell Rudolf Dr Ing Gmbh Verfahren und Anordnung zur Regelung der Farbgebung beim Drucken
GB1458358A (en) * 1973-02-05 1976-12-15 Sira Institute Method and apparatus for colour inspection
DE3007421A1 (de) * 1980-02-27 1981-09-03 Windmöller & Hölscher, 4540 Lengerich Verfahren zur herstellung eines vorlagengetreuen farbengemisches, insbesondere einer farbe eines mehrfarbendruckes

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE549962C (de) * 1932-05-04 Julius Fischer Maschinenfabrik Verfahren und Vorrichtung zum Einstellen von Musterwalzen an Mehrfarben-Rollendruckmaschinen
FR1255224A (fr) * 1960-04-22 1961-03-03 Dunlop Sa Perfectionnements aux appareils pour la production ou l'enduisage des feuilles
DE2832382A1 (de) * 1978-07-24 1980-02-14 Juergen Prof Dr Kuehlwetter Vorrichtung zur identifizierung von farben
DE2941521C2 (de) * 1979-10-12 1982-11-25 Windmöller & Hölscher, 4540 Lengerich Verfahren zum Austauschen der Formzylinder einer Flexodruckmaschine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2969016A (en) * 1955-03-18 1961-01-24 Crosfield J F Ltd Colour printing
DE2060000A1 (de) * 1970-12-05 1972-06-15 Hell Rudolf Dr Ing Gmbh Verfahren und Anordnung zur Regelung der Farbgebung beim Drucken
GB1458358A (en) * 1973-02-05 1976-12-15 Sira Institute Method and apparatus for colour inspection
DE3007421A1 (de) * 1980-02-27 1981-09-03 Windmöller & Hölscher, 4540 Lengerich Verfahren zur herstellung eines vorlagengetreuen farbengemisches, insbesondere einer farbe eines mehrfarbendruckes

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0196431A2 (fr) * 1985-03-21 1986-10-08 Felix Brunner Procédé, dispositif de réglage et moyens auxiliaires pour l'obtention d'un résultat d'impression uniforme au moyen d'une machine d'impression offset polychrome fonctionnant suivant le procédé de similigravure
EP0196431A3 (en) * 1985-03-21 1988-07-20 Felix Brunner Method, control device and auxiliary means for obtaining uniform printing results from a multicolour half-tone offset printing machine
EP0228347A1 (fr) * 1985-12-10 1987-07-08 Heidelberger Druckmaschinen Aktiengesellschaft Procédé de commande de l'alimentation en encre pour une machine à imprimer, dispositif d'impression équipé de manière correspondante et dispositif de mesure pour un tel appareil d'impression
EP0282446A1 (fr) * 1987-02-23 1988-09-14 GRETAG Aktiengesellschaft Procédé de réglage continu de l'encrage en impression en creux ou flexographique et machine correspondante
EP0337148A2 (fr) * 1988-04-12 1989-10-18 Heidelberger Druckmaschinen Aktiengesellschaft Procédé de commande de l'encrage d'une machine d'impression
EP0337148A3 (en) * 1988-04-12 1990-08-22 Heidelberger Druckmaschinen Aktiengesellschaft Method for controlling the inking in a printing press
FR2643017A1 (fr) * 1989-02-10 1990-08-17 Heidelberger Druckmasch Ag Procede de reglage de la coloration de produits imprimes
EP0394681A2 (fr) * 1989-04-24 1990-10-31 Heidelberger Druckmaschinen Aktiengesellschaft Procédé pour contrôler l'encrage dans une machine d'impression avec limitation de l'épaisseur de la couche d'encre et de l'augmentation de la valeur tonale
EP0394681A3 (fr) * 1989-04-24 1991-06-26 Heidelberger Druckmaschinen Aktiengesellschaft Procédé pour contrôler l'encrage dans une machine d'impression avec limitation de l'épaisseur de la couche d'encre et de l'augmentation de la valeur tonale
EP1666252A3 (fr) * 2001-03-27 2009-10-21 Windmöller & Hölscher KG Dispositif et procédé de réglage de l'image d'impression dans une machine d'impression flexographique
EP1862307A3 (fr) * 2006-06-02 2008-06-04 Heidelberger Druckmaschinen Aktiengesellschaft Procédé destiné au calcul des valeurs de correction dans une commande couleur ou une régulation de couleur pour une presse d'impression

Also Published As

Publication number Publication date
US4667596A (en) 1987-05-26
EP0089016B1 (fr) 1985-06-05
CA1199521A (fr) 1986-01-21
JPS58175687A (ja) 1983-10-14
DE3209483A1 (de) 1983-09-29

Similar Documents

Publication Publication Date Title
EP0089016B1 (fr) Procédé pour le réglage automatique des couleurs imprimées par les machines d'impression flexographiques imprimant en quatre couleurs
EP0196431B1 (fr) Procédé, dispositif de réglage et moyens auxiliaires pour l'obtention d'un résultat d'impression uniforme au moyen d'une machine d'impression offset polychrome fonctionnant suivant le procédé de similigravure
EP0255924B1 (fr) Procédé et dispositif pour influencer l'encrage d'une surface encrée dans une machine à imprimer
EP0272468B1 (fr) Marques de contrôle de l'impression
DE4431270C2 (de) Verfahren zur Steuerung der Farbführung einer autotypisch arbeitenden Druckmaschine
DE19703129B4 (de) Verfahren zur Bewertung der Qualität eines im Mehrfarbendruck auf einem Bedruckstoff erzeugten Druckbildes
EP1525981B1 (fr) Evaluation de la qualité des couleurs et réglage de l'encrage dans la reproduction de couleurs
DE3830121A1 (de) Verfahren und vorrichtung zur einstellung eines vorgegebenen, durch ein wertepaar volltondichte/rasterpunktaenderung definierten druckstandards bei einem autotypischen druckvorgang
CH646190A5 (de) Verfahren zur herstellung eines vorlagengetreuen farbengemisches fuer den papierdruck.
DE4343905C2 (de) Verfahren zur Steuerung der Farbführung bei einer Druckmaschine
EP0825023B1 (fr) Procédé pour déterminer des données de reglage pour la commande d'une machine à imprimer
EP0505323B2 (fr) Procédé pour le réglage des grandeurs des points de trame pour une presse rotative à imprimer offset
EP0676285B1 (fr) Gestion des couleurs dans une machine rotative offset pour feuilles
DE3543444A1 (de) Verfahren und regelvorrichtung zur erzielung eines gleichfoermigen druckresultats an einer autotypisch arbeitenden mehrfarbendruckmaschine
DE4338976C2 (de) Anordnung von mehreren Kontrollfeldern
EP0916491B1 (fr) Procédé pour déterminer des gradients colorimétriques
DE4402784C2 (de) Messfeldgruppe und Verfahren zur Qualitätsdatenerfassung unter Verwendung der Messfeldgruppe
DE4038574C1 (fr)
EP0649743B1 (fr) Procédé pour contrÔler l'apport de couleur dans une presse fonctionnant suivant le procédé de similigravure
DE102004044763B4 (de) Messfeldanordnung
EP0282446B1 (fr) Procédé de réglage continu de l'encrage en impression en creux ou flexographique et machine correspondante
DE2727227A1 (de) Einrichtung zur qualitaetssicherung von druckerzeugnissen

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

Designated state(s): CH FR GB IT LI

17P Request for examination filed

Effective date: 19831223

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): CH FR GB IT LI

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
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: 19881122

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19890331

Ref country code: CH

Effective date: 19890331

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

Ref country code: FR

Payment date: 19900228

Year of fee payment: 8

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

Ref country code: FR

Effective date: 19911129

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST