1
Josef A Huber: Process for assessing the quality of a printed product. Gretag Aktiengesellschaft, Burns Doane Swecker & Mathis, January 19, 1982: US04311914 (165 worldwide citation)

The differences between the scanned values of corresponding image points of a specimen and an original are formed by point-by-point scanning and comparison with an original. The difference values are subjected to a tone or shade correction, and then a weighting process and a minimum threshold correc ...


2
Ehrat Kurt: Identification system for individuals. Gretag Aktiengesellschaft, Pierce Schleffler & Parker, April 23, 1974: US3806874 (147 worldwide citation)

The identification unit described in this specification comprises a testing station for identifying each of a plurality of identification units adapted to be carried or worn by authorized personnel. Each unit has data stored therein which is different from the data stored in other units and includes ...


3
Hans Ott, Rolf Boegli, Ulrich Birch, Helmut Kipphan, Gerhard Loffler: Process and apparatus for the colorimetric analysis of printed material. Gretag Aktiengesellschaft, Burns Doane Swecker & Mathis, March 19, 1985: US04505589 (106 worldwide citation)

On a measuring table (1), a bridge (2) extends over a printed sheet (5) to be measured. A measuring carriage (3) carrying a three color-simultaneous measuring head is arranged on the bridge (2) for linear movement in a back-and-forth manner along a desired path on the printed sheet. For control of t ...


4
Ehrat Kurt: Self-service shop. Gretag Aktiengesellschaft, Pierce Scheffler & Parker, September 17, 1974: US3836755 (103 worldwide citation)

Equipment for a self-service shop having a check-out station for determining sales data from machine readable data relating to the type of article and its weight applied to articles purchased by a customer; the equipment comprising a container in which the customer places the articles that he wishes ...


5
Kurt Ehrat: Method and apparatus for preparing and assessing payment documents. Gretag Aktiengesellschaft, Pierce Scheffler & Parker, November 9, 1976: US03990558 (82 worldwide citation)

A method and apparatus is described for preparing and assessing machine readable payment documents such as bank or postal checks to avoid fraud. The checks are prepared by enciphering the serial number and the amount for which the check is made out with secret code data to provide a crypto number wh ...


6
Guido Keller, Helmut Kipphan: Process and apparatus for the ink control of a printing machine. Gretag Aktiengesellschaft, Heidelberger Druckmaschinen, Burns Doane Swecker & Mathis, December 4, 1990: US04975862 (58 worldwide citation)

A three-color offset printing machine produces, during the printing of sheets, color measuring strips with several color measuring fields. A gray half-tone field produced by the overprinting of three colors serves as the reference field. The color location of the reference field is compared in a col ...


7
Guido Keller, Andreas Spiess, Hans Ott, Rolf Boegli: Process and apparatus for evaluating printing quality and for regulating the ink feed controls in an offset printing machine. Gretag Aktiengesellschaft, Burns Doane Swecker & Mathis, March 10, 1987: US04649502 (53 worldwide citation)

The printed sheets are scanned, by image elements, immediately behind the last printing mechanism, with one or several measuring heads. Suitable dimensions of an image element range from approximately 1.times.1 mm.sup.2 to 10.times.10 mm.sup.2. In each image element the reflectance is measured in fo ...


8
Robert Wahli: Process and apparatus for the preparation of photographic copies. GRETAG Aktiengesellschaft, Burns Doane Swecker & Mathis, March 11, 1986: US04574692 (53 worldwide citation)

In a photofinishing operation, the correlation of order envelopes, films and the paper prints produced therefrom is carried out automatically. The order envelopes, films and the strip of paper prints are provided with the same machine-readable control number per order. These control numbers are moni ...


9
Kurt Ehrat: Method and apparatus for ciphering and deciphering messages. Gretag Aktiengesellschaft, Burns Doane Swecker & Mathis, March 20, 1979: US04145568 (45 worldwide citation)

Method and apparatus for ciphering and deciphering messages, wherein series of cipher pulses with an identical pulse distribution are generated by the transmitter and the receiver stations and said pulse distribution is determined by a secret basic code and a code which is derived from date and time ...


10
Paul J Schobi: Process and apparatus for the protection of secret elements in a network of encrypting devices with open key management. GRETAG Aktiengesellschaft, Burns Doane Swecker & Mathis, November 6, 1990: US04969188 (42 worldwide citation)

Each encryption device of a communication network is divided into a base part and a security module in credit card form. The security module contains the functional stages required for the coding/decoding of the keys of lower hierarchical levels under keys of higher hierarchical levels and thus the ...