Hitachi, Ltd.

Sukegawa Electric Co., Ltd.

Nittan Valve Co., Ltd.

Other

Kyoto University

Tokyo Institute of Technology

Japan Atomic Energy Agency

Hitachi Video Engineering Co., Ltd.

Kuniaki Miura

Isao Fukushima

Yoshinori Okada

Akira Shibata

Kenji Kano

Teizo Tamura

Takao Arai

Takaharu Noguchi

Nobutaka Amada

Michio Masuda

Atsushi Yoshioka

Masaharu Kobayashi

Yasufumi Yumde

Eiji Moro

Noboru Kojima

Koichi Homma

Makoto Shiomi

Shigeru Uchida

Keiichi Komatsu

Ryo Onose

Yasufumi Yunde

Makoto Konosu

Kazunori Kotani

Masashige Hanawa

Hiroyuki Kimura

Jun Yamada

Takashi Kubota

Hitoshi Akamine

Yasunori Kobori

Katsuyuki Watanabe

Koichi Hirose

Katashi Hazama

Mitsuru Kudo

Hiroshi Yamamoto

Hiroyuki Torii

Kazuyoshi Kuwahara

Tomoaki Takeuchi

Kunihiko Tsuchiya

Fumihiko Yamanushi

Noriyosu Hayashizaki

Noriaki Ohtsuka

Yasuji Moriyama

Susumu Otsuka

Shigeaki Kanenari

Tooru Kobayashi

Takao Aria

Nobuo Namiki

Hiroshi Nagata

Provided is a method for filling a stem-side hollow area of an engine valve with metallic sodium. The method includes injecting melted metallic sodium into a cylinder having a larger diameter than an inner diameter of the hollow area of the engine valve, forming a solidified metallic sodium rod having a substantially uniform structure in the cylinder, inserting the metallic sodium into the hollow area of the engine valve through a nozzle having a small diameter, and sealing the engine valve.

Method for filling with metallic sodium

It is preferable that metallic sodium to be loaded to an engine valve used for an internal combustion engine such as automobile engine have high purity. However, conventionally, an organic solvent remaining in micropores on a surface of the metallic sodium have been hardly attracted attention. Provided is a method for purifying metallic sodium including steps of placing metallic sodium containing organic solvent in the micropores thereof in a melting tank which is sealed, and heating the melting tank under reduced pressure to vaporize and remove the organic solvent coating the metallic sodium.

Method for purifying metallic sodium

A tritium removal device for a lithium loop contains a neutron source () for colliding protons on a lithium flow, thereby generating neutrons, a lithium tank () for the lithium passing through this neutron source () to flow thereto through a flow passage (), thereby temporarily accumulating it therein, and a lithium pump () for circulating and supplying the lithium of this lithium tank () to the neutron source () through a supply-side flow passage ('). The lithium tank () and the lithium pump (), into which hydrogen gas containing tritium therein can be easily collected, are enclosed within a hermetically sealed container () including an inactive gas therein, so that even if the hydrogen gas including the tritium therein is leaked into the hermetically sealed container (), it is removed by a hydrogen isotope removal filter.

Tritium removal device for lithium loop

A self-powered gamma detector which can hold the influence of neutron rays to the minimum, and can measure the dose of gamma rays accurately under a high neutron environment in the reactor is disclosed. The self-powered gamma detector has a columnar emitter member; a collector member arranged in surroundings of the emitter member through an insulating member, and the strength of gamma rays is measured by detecting the value of a current which flows between the emitter member and an MI cable connected with the emitter member, and the collector member. Especially, the emitter member consists of pure tungsten (W), whose inevitable impurities is in 0.03 percent by weight or less.

Self-powered gamma detector

In an information recording/reproducing apparatus for recording/reproducing a digital audio signal on/from a magnetic medium, a modulator/demodulator for modulating/demodulating the digital signal by offset quadrature phrase shift keying (O-QPSK). This technique is particularly applicable to the multi-layer recording of video and audio signals in a video tape recording/reproducing system and has the advantage of avoiding interference between the recorded digital audio and video signals at the time of reproduction.

Magnetic recording/reproducing method and apparatus

A magnetic recording and reproducing apparatus having a first recording mode and a second recording mode in which a luminance signal of a video signal is converted into FM luminance signal related to a first carrier frequency and to a second carrier frequency so as to be recorded on a magnetic tape includes a discriminating device or discriminating a recording mode in which an FM luminance signal reproduced from a magnetic tape so as to be supplied to a playback circuit has been recorded. The signal discriminating device includes an automatic gain control (AGC) circuit for absorbing a dispersion of the reproduced signal, a discrimiating circuit having a first band-pass filter and a second band-pass filter for processing an output from the AGC circuit so as to discriminate the first and second modes, a detecting circuut to which the reproduced signal is supplied in a parallel fashion with respect to the AGC circuit such that an amplitude of the signal is detected and is then compared with a predetermined value so as to obtain noise information, and a latch circuit for latching an output from the discriminating circuit such that in response to the noise information from the detecting circuit, a previous value of the outpt from the discriminating circuit is held, thus producing a discrimination output of the discriminating device.

Signal discriminating device for VTR having expanded dynamic range

A magnetic recording and reproducing apparatus of a cassette type has a first and a second recording mode converting a luminance signal of a video signal into an FM luminance signal having a first and a second carrier frequency and recording the FM luminance signal on a magnetic tape respectively. When the FM luminance signal is to be recorded according to the second recording mode, a magnetic tape having an excellent short wavelength recording characteristic is used for recording. A cassette containing this magnetic tape is provided with a configurational feature on its upper or lower half, and a detector for detecting this feature is disposed in the apparatus. When the detector detects that a magnetic tape is adapted for recording according to the first recording mode, the FM luminance signal is recorded according to the first recording mode, but when the detector detects that the magnetic tape is adapted for recording according to the second recording mode, the user can select either the first recording mode or the second recording mode as desired. A discriminating circuit is disposed in the reproducing system to discriminate as to whether the FM luminance signal was recorded according to the first recording mode or the second recording mode, and, on the basis of the result of discrimination by the discriminating circuit, the reproduced FM luminance signal is automatically processed in a processing circuit with a processing characteristic corresponding to the recording mode.

Magnetic recording and reproducing apparatus

In a recording and reproducing apparatus wherein a video signal and an audio signal are recorded on the same recording track, a signal subjected to a quadrature differential PSK modulation with PCM audio signal is generated as an audio recording signal. The audio recording signal is disposed between occupied bands of FM luminance signal and down converted chrominance signal in a video recording signal and also recorded on a track where the video recording signal is to be recorded.

Apparatus for recording and reproducing video signal and digital signal

Disclosed is a VTR of the helical scan type having a plurality of rotary magnetic heads. This VTR can select one of a first and a second signal recording forms which are different from each other, and record signals on a magnetic tape. In the first recording form, a frequency-modulated video signal including a luminance signal and a color signal and a frequency-modulated sound signal are recorded on the same track so as to be superimposed one on the other. In the second signal recording form, a frequency-modulated luminance signal and a frequency-modulated color signal are recorded separately on tracks adjacent to each other. This VTR has compatibility with respect to the recording/reproducing of two different signals.

VTR having magnetic-head array capable of recording/reproducing signals

An integrated filter circuit including at least integrated resistances and integrated capacitances, said integrated filter circuit comprising a plurality of filter circuits connected in parallel and in which at least either resistance values or capacitance values are different, a switch for switching said parallel filter circuits, and means for controlling said switch to select one of said parallel filter circuits.

Integrated filter circuit having switchable selected parallel filter

In a magnetic recording circuit with a bias current circuit adapted to superimpose a bias current from a bias oscillator on a recording signal and to supply a resultant signal to a magnetic head, there is provided a resistor for detecting the bias current flowing through the magnetic head, a rectifier circuit for rectifying and smoothing a signal developing across the resistor, and a control circuit for comparing the output voltage of the rectifier circuit with a reference voltage and producing an output signal which controls the oscillation level of the bias oscillator, whereby the bias current flowing through the magnetic head can automatically be set to a predetermined level. A variable resistor for adjustment of the bias current and adjustment step for the variable resistor can be dispensed with.

A recording circuit having means to automatically set the recording

A recording circuit for a video tape recorder which records superposedly a frequency-modulated audio signal with a frequency-modulated luminance signal and a carrier color signal converted to a low frequency band records a carrier wave signal which is frequency-modulated by the luminance signal at a substantially constant recording current within the frequency range corresponding to a range from the sync signal leading edge to the white peak. In an ordinary recording circuit, the extent of erasure of the recorded audio signal varies with the content of the frequency-modulated luminance signal when the luminance signal is recorded on the recording track of the frequency-modulated audio signal, because recording is made by increasing a recording current for a signal having an instantaneous frequency which is low. Therefore, the recorded signal which is frequency-modulated by the audio signal is amplitude-modulated by the luminance signal, and interference with the audio signal due to the change of S/N corresponding to the change of the amplitude occurs. In the recording circuit of the present invention, however, no interference is applied to the audio signal because the extent of erasure of the recorded audio signal by the luminance signal remains substantially constant irrespective of the content of the luminance signal.

Apparatus for multiplex recording and reproduction of audio and video

The IC chip consists of electronic circuits wherein voltage control oscillator whose oscillation frequency is dependent on the product of the resistance value of a resistor element and the electrostatic capacity of a capacitor element is provided; said capacitor element consists of the first variable capacitor; said voltage control oscillator comprises said capacitor consisting of said first variable capacitor; said first variable capacitor is controlled by the output obtained by detecting the output signal of said voltage control oscillator by its phase, using the predetermined reference signal, whereby the oscillation frequency of said voltage control oscillator can be made to agree with the frequency of said reference signal. Furthermore, the characteristic of said electronic circuit is dependent on a second resistor element and a second variable capacitor element; said second variable capacitor is controlled by the output obtained by the phase detection so that dispersions of the resistance value of the resistor element and the electrostatic capacity of the capacitor element in said electronic circuit are absorbed automatically.

Integrated circuit with a phase-locked loop

A filter integrated circuit having a reference level generator circuit for attenuating its input signal and generating a reference level signal, a pseudofilter circuit including resistors and a variable capacitor as filter elements, and an error amplifier unit for comparing the level of the output signal of the reference level generator circuit with the level of the output signal of the pseudofilter circuit and for generating an automatic adjustment control signal in accordance with the level difference between the output signals. The automatic adjustment control signal is supplied to the pseudofilter circuit to change the capacitance value of the variable capacitor in the pseudofilter circuit so that the output signal level of the pseudofilter circuit may become equal to the level of the reference signal. The automatic adjustment control signal is also supplied to at least one filter circuit to change the capacitance of a variable capacitor included therein. As a result, the deviation in the filter characteristics caused by deviations in the resistance of a resistor and in the capacitance of the capacitor is corrected.

Integrated filter circuit with variable frequency characteristics

Disclosed is a circuit for emphasizing a video signal in the vertical direction of a television picture for minimizing noise appearing during reproduction. In the circuit, a signal obtained by delaying an input video signal by one horizontal scanning period is positively fed back through a feedback circuit to the input of the input video signal. An amplitude difference signal between the video signal after being fed back through a positive feedback loop and the delayed video signal is produced and added to the input video signal to provide an output video signal.

Vertical contour emphasis de-emphasis circuit

Growing community of inventors

Ibaraki, Japan

Kuniaki Miura