Abstract: A transversal type automatic equalizer comprises a transversal filter having a plurality of taps separated by time delay intervals, said transversal filter receiving input signals from a transmission line, a plurality of potentiometers being connected to each of said taps to provide a tap weight and the outputs of the potentiometers being summed up to provide an equalized output signal, and said potentiometers being adjusted by an equalization arithmetic unit. The potentiometers and thereby the tap weights are adjusted according to the output of the arithmetic unit whereby an equalized output with a suppressed ripple characteristic is produced.

Abstract: In a long line transmission system, the signal level at the transmission station is pre-equalized by the value L.sub.s which is adjustable according to the signal level at the receiving station. The receiving station equalizes the received signal to the standard level at the output of the receiving station. The difference between the actual level L.sub.r at the input of the receiving station and the standard level there, is fed back to the transmission station through a return transmission line, and said difference is utilized to adjust the pre-equalization value L.sub.s at the transmission station. The ratio L.sub.s /L.sub.r is controlled to be constant by the operation of the pre-equalization level distributor installed at the transmission station.

Abstract: In a facsimile system having a carrier movable linearly in both directions with a read-head and a write head for scanning an original paper and/or a printing paper, the movement of the carrier of the facsimile system in a receiving mode is initiated by the synchronization signal sent from another facsimile system in a transmission mode, thus the operation of the facsimile system in the receiving mode is synchronized with that in the transmission mode, on a start-stop basis. Said synchronization signal is sent from the transmission station to the receiving station for every both way trip of the carrier.

Abstract: A facsimile transmitter receiver system comprising a carrier having a read head and a write head movable linearly in both directions by a pulse motor for main scanning of a printing paper and an original paper, a control circuit for applying a predetermined number of pulses to said pulse motor for each main scanning cycle. A synchronization signal is generated in each scanning cycle in both the directions in the transmission mode, and said synchronization signal received by the corresponding facsimile system in the receiving mode initiates the operation of said control circuit, thus the facsimile systems in communication are synchronized to each other.

Abstract: A frequency band compression method, using Time Compression, for use with a frequency division multiplex (FDM) signal carrying voice signal. On the transmission end, the multiplexed signal is divided into a plurality of time segments, each segment having a certain duration, then deleting a part of the each segment and time-expanding the remaining part of the segment by a sawtooth variable delay, thus lowering the frequency of the signal to a predetermined ratio. On the receive end, the signal segments are compressed by a corresponding variable delay, thus making the received frequency higher and reproducing the original multiplexed voice signals.

Abstract: In a delay equalizer having a plurality of quadratic all pass networks for equalizing the delay characteristics of a circuit, the automatic adjustment of the value of Q of each quadratic all pass network when calculated through the asymptotic formula ##EQU1## CAN PROVIDE PERFECT DELAY EQUALIZATION, WHERE Q.sub.i.sup.k is the value of Q of the i'th quadratic all pass network, and .alpha..sub.i is the step size parameter of i'th quadratic all pass network. Before applying said formula, the delay of the circuit to be equalized at the center frequency of each quadratic all pass network is measured, and said formula is calculated according to the result of the measurement.

Abstract: In a band division type equalizer having a plurality of equalizer sections, the adjustment of each of the equalizer sections is accomplished through measurement of characteristics of a transmission means to be equalized and calculation of the difference of the measured characteristics and the desired characteristics. Since all of the equalizer sections are adjusted at the same time according to the result of the calculation, the adjustment does not suffer from interaction among the sections. An adjustable variable, for instance, a variable resistor for each section is mounted in a single setting unit separable from the rest of the equalizer circuit. Thus, after completely adjusting the setting unit, the setting unit is connected to the rest of the equalizer sections, and then the desired delay characteristic can be obtained. The equalizer section is for instance a Moschytz type delay circuit.

Abstract: A Bessel function type automatic delay equalizer comprising a plurality of transversal filters each of which has an independent delay cosine equalization component having a predetermined period, and the superposition of those filters providing the desired characteristics, characterized in that, said equalizer further comprises a Bessel function generator for controlling the tap gain of said transversal filters.

Abstract: In a transmission station, the information from each channel is sampled and encoded to a PCM form having a predetermined length of bits. The group of said bits together with line number bits is called a signal block. Only significant signal blocks from all the channels are transmitted to a receiving station through a buffer memory provided at a transmission station and a common transmission line. The receiving station receives the signal blocks through a buffer memory provided at the receiving station and inserts an idle signal to the portion where the transmission station removes a signal block due to an insignificant signal block. The received signal blocks are distributed to each receiving channel, thus, the original signal is reproduced at the receiving station.

Abstract: A liner scanning device for a facsimile system comprises a carrier which carries a write head and a read head mounted on a belt w hich is moved linearly in both directions by a pulse motor. The read head is composed of the end of a flexible optical fiber assembly having an emission fiber for illuminating a spot on an original paper and a receiving fiber for detecting the reflected brightness of a cell in said illuminated spot. The write head is composed of the end of the other optical fiber one end of which is positioned at the output of a laser beam source, which heats a thermal printing paper selectively through the optical fiber. Thus the thermal printing paper is heated by a laser beam and the color of the paper is selectively changed according to the pattern to be printed.

Abstract: A read head for scanning the image information on an original paper, having an optical fiber assembly having a plurality of light emission fibers for emitting a light beam onto the original paper and a light receiving fiber for receiving the reflected light from said original paper, a transparent plate having an opaque film with a small hole mounted at the extreme end of said optical fiber assembly, the other extreme end of said light emission fiber and light receiving fiber in said optical fiber assembly being positioned in front of a light source and a light detector element, respectively, and said transparent plate being positioned in contact with or near the original paper to be scanned.

Abstract: In an automatic equalizer for regenerating a received digital signal, comprising a delay element train with a plurality of taps, a coefficient matrix circuit and a group of variable coefficient units, the structure of said coefficient matrix circuit being considerably simplified by introducing a simple adder and/or subtractor at the input and/or the output of said coefficient matrix circuit.