Abstract: A coding device in which N digital signals (time-sequential sampled data), obtained by sampling and quantizing analog video signals, are brought together in one group (N being an integer greater than two) and coded. Among these N sampled data, at least one of them serving as a reference is coded with a number of quantization bits n, which is so great that errors due to the quantization can be neglected, and for the other sampled data the difference between the reference sampled data and each of the others is compressed and coded with a number of bits, which is smaller than n. In this way, even if a coding error is produced; effects thereof are restricted within the gorup where it is produced they are not exerted on the other groups, and thus error propagation does not occur.

Abstract: A magnetic video recording/reproducing apparatus of high resolution, which excludes a phase difference introduced to a signal due to difference in characteristics between a low frequency conversion system and a high frequency conversion system by inserting an additonal signal to both systems. The additional signal is recorded together with the video signal and a phase difference is detected. The detected phase difference is utilized for regulating the phase difference in the respective frequency systems.

Abstract: A control circuit comprises a first counter for counting up stepping pulses and counting down the number of steps of a stepping motor, a memory for storing therein a drive timing of the stepping motor, a variable timer for converting a data in the memory to a real time, a second counter for counting up an output signal of the variable timer when a count of the second counter is smaller than a count of the first counter and counting down the output signal of the variable timer when the count of the second counter is equal to or larger than the count of the first counter, and a drive circuit for driving the stepping motor in accordance with the output signal of the variable timer.Signals to set the first counter in the count-up mode and the count-down mode are synchronized with two clock signals having the same frequency and different phases.

Abstract: A magnetic storage disk tracking system employing a stepping motor is operable to compensate the tracking error within a certain expected range caused by the hysteretic movement of the motor. The system incorporates means for recognizing the track to which the magnetic head is positioned and memory means in which is stored data for compensating the positioning error depending on each track. The stepping motor is controlled through the excitation voltage of each winding under modulation in terms of the magnitude or duty cycle in compliance with the stored data.

Abstract: A magnetic head suitable for use in a magnetic disk. In a magnetic head in accordance with the present invention, a read/write head and an erase head are placed side by side in the rotation direction of the magnetic disk. A gap in the read/write head is placed at a distance of l from a pair of gaps in the erase head. In addition, the read/write gap in the read/write head is deviated by a distance L in the external circumference direction with respect to a pair of erase gaps in the erase head.

Abstract: A tracking servo system for a magnetic recording and reproducing apparatus uses a flexible magnetic disk having thereon at least first, second and third tracks each of which includes a data track portion and a pair of servo track portions located on both sides of the data track portion. Tracking signals having different frequencies are recorded on the first, second and third servo track pairs. Servo and data heads are formed in a unitary structure. When the data head records an information signal on the second data track portion or reads out the recorded information signal therefrom, the servo head reads out the tracking signals recorded on the first and third servo track portions.

Abstract: A tape recorder comprises, in its signal recording path, a variable gain circuit compensating the sound recording sensitivity of a magnetic tape and two variable equalizers compensating the frequency characteristic of the magnetic tape in the intermediate and high frequency ranges respectively. Reference signals at three different frequencies are successively supplied to the signal recording path to be recorded on the magnetic tape, and the signals of different reference frequencies are successively reproduced from the magnetic tape to be then arithmetically processed so as to optimize the gain of the variable gain circuit and the degree of frequency characteristic compensation by the first and second variable equalizers.

Abstract: A magnetic recording and reproducing apparatus comprises a source for producing test signals, a variable-gain amplifier, an equalizer, a recording bias generating circuit, a control unit for supplying control signals to the amplifier, equalizer and recording bias generating circuit, a memory and an operating circuit unit.

Abstract: An alarm device for a vehicle comprises sensors for detecting abnormal states of the vehicle, a logic circuit for receiving the outputs of the sensors and producing one or more alarm speech designation signals and an alarm speech generator responsive to the alarm designation signal. The logic circuit includes a priority circuit for determining the order of precedence of the abnormal states represented by the detection signals on the basis of the degree of emergency, so that the alarm speech is concerned with the most emergent alarm when two or more abnormal states are detected simultaneously. The logic circuit may further include a switch circuit for disabling at least one of the detection signals so that a vehicle driver having taken notice of particular alarms is not disturbed by excessive alarming.