Abstract: A spindle servo circuit controlled according to a time base. Fine time base tuning is performed in a clock driven CCD. In a scan mode, tracks are alternately reproduced and jumped. The fine tuning is turned off at the start of jumping (which occurs after a full video field has been written into a video memory) and the center frequency of a VCO clock is decreased so as to slow the shifting of the CCD.

Abstract: A time base control system for a spindle servo motor in which the time base is both coarsely controlled and finely controlled. According to the invention, when the recording head is alternately tracking and jumping tracks, the controllable range of the fine tuning is widened and the course tuning is gradually increased.

Abstract: A protection channel monitoring system for monitoring a protection channel in a digital communication network comprises a transmitter (31) transmitting a check signal converted and split into a plurality of AMI code signals through the protection channel. The check signal is formed from a pseudo random signal provided by a pseudo random signal generator (15) driven by a pulse signal having a 1/N (N being an integer larger than 1) frequency of a clock pulse signal. The check signal comprises two predetermined N-bit code patterns each comprising logical "0" and "1" level bits. A receiver (32) receives the split AMI code signals through the protection channel and decode the AMI code signals to the NRZ code signals by sampling technique using a sampling signal being derived from one of the received AMI code signals and having the 1/N frequency of the clock pulse signal. Condition of the protection channel is decided by comparison of the decoded NRZ code signals.

Abstract: In radio digital transmission system including at least one repeater station, a channel monitoring circuit of each repeater station comprises, besides the conventional inter-terminals fault detection circuit using parity check system, a control bit inserting circuit for inserting a parity control bit into the received signal, a control bit extracting circuit for extracting the control bit from the received signal, a logic circuit for logically operating the output signal of the conventional fault detection circuit and the output signal of the control bit extracting circuit, and a second fault detecting circuit responsive to the output signal of the logic circuit for detecting the fault on the transmitting line between the repeater station and an immediately preceding station.

Abstract: A digital signal communication system has a transmitter for differentially converting first digital signals of n trains (n is an integer of 3 or larger) into a second digital signal of n trains comprising a plurality of words. Responsive to the second digital signals, a modulated signal is provided with 2.sup.n (=N) modulation levels, which are transmitted. A receiver responds to the modulated signals, and demodulates them to provide signals of n trains corresponding to the second digital signals. This demodulated signal is differentially converted to provide n trains of signals corresponding to the first digital signals. The Hamming distance between two words of said second digital signals corresponding to the adjacent two modulation levels is either 1 or 2 and the numbers of the Hamming distances of 1 and 2 equal N/2, respectively.

Abstract: An apparatus includes a sealed vessel, a crucible received in the sealed vessel to hold a first molten liquid of III-V compound semiconductive material and a second molten liquid of an encapsulating material overlying the first molten liquid, and floating member having an opening for defining the cross sectional outline of a single crystal while being grown and positioned in the interface between the first and second molten liquids. The floating member is made from a mixed material consisting essentially of at least one of oxides of yttrium and the lanthanum series elements, alumina and silicon nitride each in a prescribed amount.

Abstract: A granular sorbic acid having improved properties is prepared in a very simple manner without need of any particular preparation as in conventional methods, i.e. by granulating by extrusion, powder having particle sizes of ASTM No. 70 sieve pass in the presence of water or water containing a surfactant. The resulting granule has a suitable hardness and hence scarcely collapses at the time of drying after granulation and subsequent handling, but has a rapid dispersibility into foods at the time of its use.