Bobst Sa

J. Bobst & Fils S.a.

Roger H Roch

Olivier Porret

Vaclav Vitous

Patrick Monney

Nathan Stern

Jean Grob

Panayotis Kammenos

Claude Chablais

Jean J Barny

A process for correcting misregistration between imprinted images from successive printing stations comprising measuring the width of the imprinted image of each station and comparing the width to determine any difference, and creating a correction signal if a difference does exist to change the humidity in the web passing through the printing unit. The device includes photoelectric devices for determining the width of each image created at each station, an electronic device for comparing the width of each image and, if a difference exists, creating an error signal which is applied to the first drying unit and a secondary error signal applied to the second unit to correct the humidity of the web leaving each dryer.

Process and device for controlling the humidity of a web on a printing

During, for example, package production, printed sheets are carried by gripper bars through a cutting station of a machine. Front waste strips are removed from the printed sheets and are carried to an ejection device, but before reaching the ejection device, a camera and flash scanning unit scans the area of the front waste strip which has been marked with color registration marks and also includes at least a portion of a cut edge. An image processing unit compares this sample image to a reference image to conduct a quality check on the precision of the printing and cutting registration.

Method and apparatus for checking printing and cutting quality in a

A process consists of detecting a printed registration mark composed of recognition signals and of a color pilot mark, comparing the image of the signs of the printed registration mark to the signs of a virtual reference registration mark, then defining a basic area for each sign, calculating a geometric center of every basic area, detecting any color pilot mark in these basic areas, calculating and memorizing the geometric center for the detected pilot mark, measuring an offset position between the geometric center of the basic area and the geometric center of the detected color pilot mark and utiliziing the measured offset position for controlling a misregistration correction appliance of a printing press. The device for accomplishing the process includes an arrangement for performing each of the above-mentioned steps.

Process and device for detecting print registration marks on a web from

The process and the device for measuring the displacement of a web within a multi-color rotary printing press by means of a mark simultaneously printed with each color in an area free of any printing characterized by the mark passing beneath the photodetector arrangements for generating a signal. The method and the device are further characterized by the fact that the pair of photodetectors are arranged side-by-side along a crosswise line with the edges of the field for each detector arrangement being positioned above the web at the expected position for the passage of the center of the crosswise symmetrical mark and the crosswise displacement of the web is determined by the difference between the intensity variations of the signals created by each of the two photodetectors when the mark passes therethrough.

Process and device for measuring displacement rates of a web running

A CAMERA-FLASH unit of a feeder table of an infeed station belonging to a machine converting sheets into package is disclosed. The CAMERA-FLASH unit shoots an image of the color register marks printed previously on every sheet. The CAMERA-FLASH unit operates jointly with an IMAGE PROCESSING SYSTEM having previously memorized a reference image from a model sheet. Owing to an image process comparison of the images shot from the successive sheets to the memorized image of the model, it is possible to check whether the quality criteria of the run are fulfilled.

Cut-to-print quality monitoring in a package producing machine

A method and apparatus for controlling the setting of the components of a printing machine use a calculating unit which receives all of the data regarding the operating status of each of the components to be controlled. The calculating unit process data relating to the running of the web and compares the data with data obtained by read heads, also sensing the web. The data from the read heads is supplied to the memory of a computer, the computer also having a touch screen for permitting direct control and setting of the components. A printer and a photographic recorder are coupled with the touch screen for displaying the images thereon.

Method and device for controlling the setting of the components of a

A box making machine comprises a feed station, a positioning station, a printing station including four printing units, a cutting station with a creasing unit, a slotting unit and a cutting unit, a folding-gluing station and a stacking and delivery station, all driven by D.C. motors. The D.C. motors control is achieved by the electrical shaft coupling driven by a driving device which comprises a command control unit having a code generator, a synchronization circuit for each motor and a curved generator for one of the motors, a calculating unit including a microprocessor, input/output circuits and an input circuit with switches, a signal conditioning unit with an element for sense discrimination and multiplication, and a signal conditioner, and a command logic unit including a logic drive selection circuit, a logic starting circuit and a logic manual command circuit.

Machine for manufacturing folded boxes

An apparatus for controlling the movement of a web of material, which is being continuously supplied to a machine which operates sequentially on a portion of the web as each portion is at a standstill, characterized by the apparatus including a feeder for feeding the web at a continuous rate of speed and a web take-up device for engaging the web as it exits the feeder to absorb the web being supplied by the feeder for a period of time that the portion of the web is being acted on by the machine and is in a stationary or standstill position. The web take-up device includes a pair of first members mounted in a pair of spaced side frames for rotation on a first axis, a web guide member having a second axis and a structure mounting the web guide member to extend between the pair of first members with the second axis being eccentric to the first axis. The structure for mounting the web guide members includes a control screw for varying the amount of offset of the second axis from the first axis, and a cam or lever arrangement for varying the angular position of the second axis during rotation of the pair of first members on the first axis. The take-up device also includes a device for compensating for the weight of the guide member including a second screw coupled to the first screw to move a counterweight during rotation of the first screw.

Apparatus for controlling the movement of a web of material continuously

In a printing machine, a device for introducing a continuous web of paper to the printing station, the device having apparatus to continually measure the coefficient of elasticity of the web and apparatus for developing a tension on the web as a function of the measured coefficient of elasticity. The web is fed against two tension measuring devices in conjunction with two traction rollers having slightly different radii from which the coefficient of elasticity can be calculated electronically.

Equipment for introduction of a strip of paper, cardboard or similar

Apparatus for the continuous measurement of the elastic coefficient of a traveling strip, wire or ribbon, is characterized in that it employs first and second means for driving the strip arranged one behind the other in the direction of motion of the strip. The second driving means drives the strip at a speed different from that of the first driving means and first and second tension measuring devices are disposed in front of the first and second driving means, respectively, and deliver respective quantities which are proportional to the tensions measured thereby. A comparator circuit is provided for determining the difference in the measured tensions, this difference being proportional to the elastic coefficient of the strip.

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Cossonay-Ville, Switzerland

Roger H Roch