Abstract:
A disc is provided with the equal-interval pits along tracks, at which digital signals are recorded bit by bit. Such a disc is rotated at the constant angular velocity. A signal processing apparatus according to the present invention detects the linear velocity of the track which is at present followed by a pickup. The filtering of a source signal to be recorded and the analog-to-digital conversion of the filtered signal, in the signal processing for recording, are controlled and timed in accordance with the detected linear velocity. Further, the digital-to-analog conversion of a signal read out from the disc and the filtering of the converted signal, in the signal processing for reproducing, are also timed and controlled in response to the detected linear velocity. Thereby, a disc memory device having the large storage capacity and suited for the random access memory can be realized.
Abstract:
An inverter in the D.C. power transmission is controlled by gate pulses which are synchronized with voltages of an A.C. system and whose interval is constant for respective arms of the inverter. Simultaneously therewith, in order to prevent the inverter from causing a commutation failure due to a fault in the A.C. system, a control voltage for making the gate pulses is corrected by the use of the lowest one of the phase voltages or line voltages of the A.C. system. The control voltage becomes greater as the phase voltage or the line voltage lowers more from a rated voltage. When the control voltage increases, the gate pulses are provided at a timing of a larger advanced control angle so as to maintain the extinction angle constant.
Abstract:
An information recording and erasing method and apparatus of an optical memory medium including a substrate, a guard film, and an intermediate layer portion so disposed between said substrate and said guard film as to include at least a recording material layer having a phase changing with temperature and include at least one good conductor layer, comprising the steps of supplying magnetic flux varying relatively to said good conductor layer to generate eddy currents within said good conductor layer, and heating said recording material layer with heat generated in said good conductor due to the eddy current loss to effect information recording and erasing with respect to said recording material layer.
Abstract:
In the present invention, a micro Fresnel lens in the shape of a thin film is used. A lens driving member constructed of piezoelectric transducers or of magnets and coils is disposed around the lens. The focus of the lens is adjusted by controlling applied voltages to the piezoelectric transducers or the coils.
Abstract:
A gate controlling apparatus for a thyristor valve including a plurality of series connected thyristors controlled by a narrow gate pulse. The apparatus includes means for judging whether the thyristor valve is to be in the conductive state or not, means for detecting a forward voltage across at least one of the thyristors in the thyristor valve, and an AND circuit for generating an output at a time when an AND condition between the respective outputs of the judging means and the forward voltage detector means is satisfied. The apparatus further includes means for detecting a period of inverse voltage across at least one of the thyristors in the thyristor valve. The forward and inverse voltages may be, respectively, detected by detecting the forward and inverse voltages of specified thyristors.
Abstract:
The present invention employs as a recording medium a metal or alloy which exhibits an intercrystalline transition before and after writing. In the present invention, two light beams of unequal wavelengths are used so as to write information with the light beam of the longer wavelength and to erase information with the light beam of the shorter wavelength. In changing a written content, a wavelength with which the reflection rate of the recording medium increases is used.
Abstract:
A combustion control method wherein manipulated variables or the amounts of fuel and air in at least one combustion zone of a boiler are regulated so that both the amount of nitrogen oxides and the amount of unburned coal in the ash at an outlet of a burner furnace or at least one of them passes the regulation standards and satisfies the requirements for operating a plant. The method is characterized by varying the amounts of fuel and air in performing trial operations on manipulated variables to evaluate the nitrogen oxides at the furnace outlet, the unburned coal in the ash at the furnace outlet and the stability of combustion, and declaring as optimum manipulated variables those amounts of fuel and air used for performing the trial operations which achieve results such that the combustion is found to be stabilized, at least the nitrogen oxides at the furnace outlet satisfy the requirement and the thermal efficiency of the boiler is judged to be at the highest level by a boiler thermal efficiency judging section.
Abstract:
A thyristor valve includes a plurality of thyristors connected in series and series circuits each including a capacitor and a resistor and connected in parallel with each thyristor. A pulse from a pulse generator for firing the thyristors is applied to them at the beginning of a prescribed period of conduction of the thyristor valve when voltage across the selected one of the thyristors is forward. An output signal of a current detector provides a firing pulse to all thyristors when the valve current exceeds a predetermined current value during the prescribed period of conduction of the thyristor valve.
Abstract:
A light spot determining a first condition that an optical recording medium is cooled after being heated to a temperature exceeding a first temperature and a light spot determining a second condition that the optical recording medium is cooled after being heated to a temperature exceeding a second temperature higher than the room temperature and not exceeding the first temperature higher than the second temperature, namely, the two light spots are radiated onto the optical recording medium and in the same guide track thereof wherein signals are recorded and erased on the optical recording medium by controlling the spot diameter of each light spot and/or the light intensity thereof.
Abstract:
This invention relates to the supervision of a combustion state of a combustion furnace. A flame formed concentrically with the direction of a fuel jetted from a burner being the center is measured from its side, and two oxidizing flame zones as high luminance zones are extracted. Using the shape parameters of the flame, an index for reducing NOx and unburnt components in ash are calculated and estimated so as to supervise the combustion state. The positions or centroids of the flames and the distance between the centroids are used as the shape parameters, and the flame shape is divided into two zones for easy display of each zone.