Abstract: A digital signal transmitting system includes a digital signal generator, such as, an A/D (analog-to-digital) converter, for producing digital information signals representing music or data, and a control signal generator for producing a frame synchronizing signal and service bit signals which are time division-multiplied with the digital information signals for producing a composite digital signal. Further, a terminal number and a scramble key code are time division-multiplexed on the service bits within each different frame of the composite digital signal so as to make available the scramble key code at a terminal unit or receiving side of the system.

Abstract: A digital signal transmitting system includes a signal generator for producing time division-multiplexed digital audio signals and service bit signals, a modulator for modulating a carrier in accordance with the time division-multiplexed signals and a transmitter to transmit the modulated carrier through a CATV (cable television) transmission line. In a receiver, the service bit signals are decoded so as to control the channel changeover of a television receiver when an emergency broadcast signal is transmitted. A muting control circuit is also provided so as to mute an audio signal from a D/A (digital-to-analog) converter.

Abstract: In order to take advantage of an ink jet generating unit for preparing hectographic printing masters, solid ink is proposed. The solid ink is prepared by dispersing dye stuff of more than 10 percent by weight in a hydrocarbon of the thermally dissoluble type. Various types of apparatuses each incorporating the ink jet generating unit are also provided.