Abstract: A system for generating a special calling signal to be transmitted from an aircraft to a ground station comprising two parts of repeated groups of 7-unit binary code signals, each of which parts or groups has a constant ratio of 1 and 0 value bits, but has a different ratio for each part or group. The first part or group comprises alternating signals of "idle time" with two successive signals representing the tens and units digits of the call number of one of a hundred different ground stations to be called. This alternate sequence of tens and units signals is repeated a sufficient number of times so as to avoid any error in the reception of a signal from this part and also to place the receiving ground station in phase and synchronism with the calling station in the aircraft. Then the second part or group of the whole calling signal is transmitted which second part comprises three successive separate message signals which are alternately repeated in succession every fifth signal interval.

Abstract: An improvement in applicant's co-pending application on a system for the transfer of point of time and direction of a transition between two states of an input by means of a code word of a predetermined plurality of bits, which improvement comprises using at least one less bit in the code word for indicating the direction of transition. The apparatus for carrying out this system comprises at a transmitter a device for scanning the input signal at a predetermined numbered of successive timed intervals corresponding at least to the number of bits in the code word to be generated, determining which interval or zone the transition in the binary input signal occurred, and generating the resulting code word in an encoder comprising logic circuits and a shift register having the same number of stages as bits in the code word.

Abstract: A system for converting multi-unit 1 and 0 bit binary code signals into one less unit multi-unit 0, + and - bit ternary code signals with a D.C. (direct current) component and having the same number of 0-bits or units in each signal. This conversion is accomplished by dividing each binary word code or signal into two groups of units or bits, converting one group to form a balance code with one less unit or bit than the binary code and a constant number of 0-bits, and converting the other part of each binary word for controlling the conversion and distribution of the + and - bits from the 1-bits in the code words of the first group. In the event there are more + bits than - bits or vice versa in a code word, an inverter is provided for inverting the + and - bits in the next word containing the same unbalance of + and - bits, so that any D.C. component produced by such an unbalance in one word will be eliminated or counterbalanced by inverting the next following word with the same unbalance.

Abstract: The invention relates to a method for the automatic recognition of characters, preferably of figures, which may be hand-written on an information carrier provided with an arrangement of demarcated rectangles- one for each character. These handwritten characters are projected on to a matrix, where a camera tube ensures the scanning of the matrix, and the information thus read is recorded in a store and subsequently handled by a processor.A device for carrying out this method comprises a character pattern manipulator connected to the store in the processor, the output of which manipulator is connected to a number of properties of signals derived from scanning the characters. This manipulator comprises means for copying or transferring the information stored in the processor to other storing matrices, rotating the information stored therein in successive 90.degree. turns, shifting and dividing the stored information, and erasing undesired information parts from the rectangles.

Abstract: Device for marking or writing a parallel bar code onto a document such as a postal article, comprising a number of parallel separately electromagnetically selected printing-styli and cooperating spring, crank, lever, and stop means for moving the end of each selected stylus toward and across or along the surface of the document to write or mark a bar thereon.

Abstract: System for transmitting a series of bits with an indefinite length by transmitting and receiving between two stations parts of the series in balanced blocks and maintaining automatic synchronization of said blocks by generation of two types of similar framing blocks recognizable by a special signal in a fixed place in each framing block. These framing blocks also include the code number of the channel then to be transmitted. One type of framing block is generated when a loss of phase is detected in said bits at one station, which one type of framing block is continuously transmitted to the other station whereupon receipt thereof causes the generation of the other type of framing block at the other station. This other type of framing block then is continuously transmitted back to said one station, until it is detected at said one station indicating that reframing or synchronization has occurred, so traffic or information blocks can be and are resent again from said one station.

Abstract: A method for indicating the free-line state of a subscriber's line connected to a terminal exchange in a binary data communication system comprising generating and transmitting to the exchange a special code word or byte of a plurality of a fixed number of "0" and "1" bits, such as alternate "0" and "1" bits. This special code word is sent after the closing signal at the end of the communication or traffic, which closing signal comprises a byte of only one "1" bit and nine "0" bits, and before the start-again-of-traffic signal, which start signal comprises a byte of only one "0" bit and nine "1" bits. The special free-line state code signal or byte not only indicates the line is free but also can, by the frequency of its alternate bits, indicate to the exchange terminal its modulation rate so that the subscriber can be automatically connected for the next traffic at this rate.

Abstract: Remotely controlled electric printer, to which each character to be printed is applied as m groups of n bits, comprising a set of n rulers or print bars, the total thickness of which is equal to the height of said character or a line thereof, each character having a width of m bits. Electromagnetic means are provided capable of shifting the print bars transversely with respect to one another, and there is a cross bridge or anvil that can be moved along said bars. Paper or some other printing carrier is provided between the cross bridge anvil and the bars. The electromagnetic means are so arranged that they can shift the rulers or bars transversely with respect to one another in accordance with the n-bit groups so that the rulers thereby strike the paper against the cross bridge anvil.This anvil is stepped along the line in m equal steps for each character by a pawl and rack mechanism which also is operated electromagnetically by a separate electromagnetic means.