Abstract: A rotary anode for use in an X-ray tube has a graphite substrate plate, an intermediate layer made of a metal that does not react with graphite, and an X-ray generating layer provided on the intermediate layer for generating X-rays when electron impact is applied. The intermediate layer is a rhenium film having an equiaxed grain structure. A method for manufacturing such a rotary anode is proposed. The method has the step of forming, on a graphite substrate plate, an intermediate layer of rhenium by subjecting a metallic chloride to the thermal decomposition CVD process at a substrate temperature of 1200.degree. C. or more. The method further has the step of forming, on the intermediate layer, an X-ray generating layer of tungsten or tungsten-rhenium alloy by subjecting a metallic fluoride to the hydrogen reduction thermal CVD process.

Abstract: A readout circuit in magnetic recording device is disclosed, in which a test data signal for detecting an error in the characteristics of an automatic equalizer is recorded in a predetermined position of each track of a magnetic recording medium. In readout mode, a test data signal for a selected track is read out first, and this signal is compared with a reference signal dependent on the system conditions to determine an error from the reference signal. The optimum equalization coefficient is determined to eliminate this error from the reference signal and set in the equalizer. The data is readout under the optimum equalization characteristics thus set.

Abstract: A readout circuit in magnetic recording device is disclosed, in which a test data signal for detecting an error in the characteristics of an automatic equalizer is recorded in a predetermined position of each track of a magnetic recording medium. In readout mode, a test data signal for a selected track is read out first, and this signal is compared with a reference signal dependent on the system conditions to determine an error from the reference signal. The optimum equalization coefficient is determined to eliminate this error from the reference signal and is set in the equalizer. The data is readout under the optimum equalization characteristics thus set.

Abstract: In a waveform processing circuit comprising a delay line for delaying a signal outputted from a ring type magnetic head reproducing a perpendicular magnetization recording, an attenuator for attenuating the signal delivered out of the ring type magnetic head, and a differential amplifier for receiving outputs from the delay line and the attenuator, wherein a waveform of the signal is processed to discriminate a position of magnetization transition based on the waveform of the signal; the delay time .tau. of the delay line is selected to satisfyv.multidot..tau..ltoreq.gwhere, v is a relative speed between the recording medium and the magnetic head and g indicates the gap length of the magnetic head.

Abstract: A circuit for detecting the variation of resistance of a variable-resistance element comprises a pair of grounded-base transistors with their base electrodes provided with different base voltages and with their emitter electrodes connected to both terminals of the variable-resistance element so that the voltage between both terminals of the element is kept constant. The current density of the variable-resistance element does not vary when the resistance of the variable-resistance element varies, whereby the lifetime of the element can be prolonged.

Abstract: In a current driving circuit which supplies a two-terminal load with current to be inverted in accordance with input information, a current driving circuit according to the present invention comprises a load whose one-side terminal has its potential fixed, circuitry to supply a non-fixed side terminal of the load with a direct current, and circuitry to supply the non-fixed side terminal with a current having a magnitude double that of the direct current and a polarity opposite to that of the direct current, while switching it in accordance with input information. Owing to such construction, the number of terminals to be led out from the loads can be reduced, and a load current can be inverted at high speed. In addition, reliability can be enhanced because the assembling process is simplified.