Gretag Aktiengesellschaft

Ernst Huber

Kurt Ehrat

Rino Ernst Kunz

Fred Mast

Josef A Huber

Urs Murbach

In a scanning densitometer the mobile head is connected by means of an optical fiber cable with stationary parts of the apparatus. The optical fiber cable is looped around a cable drum and guided by it. The cable drum is suspended by means of two supporting cord layouts looped around it in opposing directions in a rotating manner parallel to the linear path of motion of the measuring head. The supporting cord layouts are mounted stationarily on the apparatus and one of them contains an equalizing spring. This type of a cable conduit is highly protective and therefore particularly suitable for mechanically sensitive parts, such as for example, optical fiber cables.

Cable conduit apparatus

In the resonator of a laser generator, variable mode selective structure is provided to permit electrically actuated adaptation of beam parameters to required operating conditions. Such structure can be implemented with one or more pivotal plates, each having a different aperture, that are selectively pivoted into the beam path to effectively provide a variable mode diaphragm. In another embodiment, a spatial light modulator comprising a reversing prism with a variable position concave plate positioned adjacent its reflection surface and operating according to the optical tunnel effect can be used to selectively vary the effective diameter of the laser beam.

Laser processing apparatus with means for selectively varying the

A device for guiding a strip so that it is kept in a predetermined lateral position as the strip moves from a supply to a take up reel. The device includes mechanical sensors sensing the lateral edges of the strip, the sensors being coupled by a differential linkage system to a frame in which is mounted a pair of rollers, one each side of the strip and in contact therewith. The frame is pivoted about an axis perpendicular to the strip so that if the strip shifts laterally the sensors move the differential linkage to pivot the frame and thereby cause the rollers, one of which is driven or braked, to impart a component of motion to the strip to move it back to its initial position.

Strip guiding device

A gripper drum having in the peripheral surface thereof a number of apertures aligned in rows running parallel to the rotational axis of the drum, the rows defining an active suction zone. Each row of apertures is connected to a duct located below the surface of the drum and each duct is connected by a conduit to a bore in a stationary part of the drum, the bore being connected to a source of suction so that as the drum rotates about the inner stationary part suction is applied to the apertures. Pistons, one for each duct, are mounted on a plate which can be moved to insert the pistons into one end of each duct respectively, the opposite ends of the ducts being closed thereby sealing off the apertures from the suction source and altering the width of the active suction zone on the periphery of the drum. The conduits are connected to positions on the ducts progressively remote from the ends into which the pistons are inserted. The drum can comprise an annular outer part, having the apertures, ducts and conduits, which rotates about a stationary cylindrical part having a groove in its periphery connected to the bore for the suction source. The conduits are aligned with the groove so that on rotation of the outer part suction is applied first to one row of apertures and then to succeeding rows.

Gripper drum

A method and apparatus for detecting printing faults or errors in a sample of printed material, such as a bank note, by determining the relative positions of corresponding text on the sample and each of a number of original bank notes, each having been printed by a different printing process used in printing the sample combining the text of the originals optically or electronically taking into account the positions of the text in the originals relative to the text on the sample resulting from superimposition of the text produced by each of the printing process used to produce each original, and comparing the text of the sample with the total combined text. The relative positions of corresponding text on the sample and originals is determined by scanning the sample and originals and obtaining reflectances values at each of a number of corresponding raster points and correlating the corresponding reflectance values to obtaining the relative position values.

Method and apparatus for testing the print quality of printed texts,

A device for adjusting the composition of the spectrum of a light beam. At least one filter is adjustable at right angles to the axis of the light beam. The filter consists of two separate parts and means are provided for the joint stepwise moving of both filter parts to said axis and away from it. Thereby both filter parts are equidistant from the axis. The filter parts are moved stepwise so that the change of intensity of the light beam effected in each step remains substantially constant. The filter parts are connected to a stepping drive motor by means of traction cables the ends of which are guided over a respective cam plate which is torsionally connected to the axle of the drive motor. The cam plates have substantially the shape of a logarithmic spiral. Two spaced apart mounting plates are provided between which at least two, preferably three or four two-part filters, each with the traction cable belonging thereto, are arranged in different planes. The drive motors are positioned at the surfaces of the mounting plates.

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Wettingen, Switzerland

Ernst Huber