Abstract: A power supply unit has a capacitor unit for supplying electric power to a load. The capacitor unit has at least two blocks each having a plurality of electric double-layer capacitors connected in series. The manner of connection of the at least two blocks is changed over between series connection and parallel connection in dependence on an output required by the load. A switching regulator is connected to the electric charge-storing device. An electric vehicle having the power supply unit installed thereon is also provided.

Abstract: In a disk drive unit, a top cover, a front cover and a loading base attached with a body module cooperatively form a substantially closed receiving space for an optical disk. The front cover is provided with a dustproof shutter which closes the foregoing receiving space except upon insertion or ejection of an optical disk cartridge including therein the optical disk. Further, a dustproof cap is attached to the body module so as to cover the underside of the body module where a circuit board is disposed for processing signals relative to an optical head. A hermetically closed space is formed between the underside of the body module and the dustproof cap, in which the circuit board is accommodated.

Abstract: A shared vehicle rental system has a plurality of motor vehicles, a parking area for a plurality of users to rent motor vehicles therefrom and to return motor vehicles thereto, and a control center for supervising the motor vehicles. The shared vehicle rental system registers the users in a plurality of groups depending on a usage time zone in which the users use the motor vehicles, identifies registration information of the users which is recorded on IC cards of the users, and supervises the motor vehicles and the parking area based on the registration information of the users.

Abstract: Data signals such as a pseudo noise pattern and character data are transmitted along with voice signals over one voice signal channel, thereby allowing an accurate measurement of communication channel quality during communication or enabling concurrent transmission of both voice and character information over one communication channel. At the transmitting end, a silence interval is detected by a voice detector, and a selector is controlled so that a PN pattern, with a start signal and an end signal appended at the start and end thereof, is substituted in the silence interval. At the receiving end, the start signal and end signal are detected by a silence notification frame detector, and a selector is controlled so that background noise is substituted in the intervening period.

Abstract: In an optical disk drive for recording and reproducing data out of an optical disk, a carriage locking mechanism has an engaging member which is rotatable in a plane parallel to a base member. This reduces the space occupied by the engaging member in the direction of height of the base member. As a result, the overall thickness of the disk drive is successfully reduced. Moreover, since a notch is located at a position where the engaging member interferes with a yoke member, the height of the disk drive is further reduced.

Abstract: A radar system is designed to allow switched use of a pulse radar mode for detecting a target at a long distance away and a phase-difference radar mode for detecting a target at a short distance away, whereby target detection can be performed from a very close range to a long range with high accuracy. Also, the pulse radar mode enables detection of a plurality of targets in different ranges.

Abstract: A plurality of radar devices are provided on and along the periphery of a vehicle for monitoring in different directions. While sequentially switching the radar device to be used for the monitoring operation in response to a transmission-enable signal, a processing device detects, for each direction, presence of and distance to an obstacle or object on the basis of a phase difference (time difference) between signals transmitted and received via the corresponding radar device. Thus, the processing device causes an image display device to show the detected conditions around the vehicle and also causes a sound synthesizer to output a sound message to call the vehicle operator's attention.

Abstract: A magneto-optic disk apparatus is provided with a cartridge receiving a magneto-optic disk, a loading mechanism for moving a holder with the cartridge being set therein to an unloading position or to a loading position, and a magnetic head for applying a magnetic field in close vicinity to the magneto-optic disk, wherein the apparatus further has a support arm supporting the magnetic head and journaled as rotatable between a far position and a near position to the magneto-optic disk, a first elastic member for urging the support arm toward the far position, and a rotating member for rotating the support arm to the near position against an urging force of the first elastic member in synchronism with movement of the holder to the loading position and rotating the support arm to the far position by the urging force of the first elastic member in synchronism with movement of the holder to the unloading position.

Abstract: The first aspect of this invention relates to a peak data extracting device used in picture processing devices. The peak data extracting device comprises a DDA (data differential analysis) computing unit, an peak filter and a sorting unit. The computing unit gives Hough curves (sine curves) based on points to be processed on an original picture. The peak filter extracts peak data. The sorting unit sorts the peak data extracted with the noise components removed.The second aspect of this invention relates to a rotary motion recurrence formula computing device which are used in the DDA computing unit. The device computes the rotary motion formulax.sub.i+1 =f.sub.x (x.sub.i, y.sub.i, .epsilon.)y.sub.i+1 =f.sub.y (x.sub.i, y.sub.i, .epsilon.).

Abstract: A method for feedback controlling an air/fuel ratio of mixture supplied to an internal combustion engine to a target air/fuel ratio, which uses an output signal of an oxygen concentration sensor. The sensor's output signal is proportional to the oxygen concentration in the exhaust gas of the engine. When the target air/fuel ratio is set at a stoichiometric air/fuel ratio, the air/fuel ratio of the mixture is varied by a small amount around the stoichiometric value if the air/fuel ratio of mixture supplied to the engine is detected to be in a predetermined air/fuel ratio range which includes the stoichiometric air/fuel ratio. The determination of the air/fuel ratio is calculated from the output signal of the oxygen concentration sensor.

Abstract: A device for detecting and measuring the concentration of a gas in a mixture of gas such as oxygen in the exhaust gas of an internal combustion engine and circuits for using that measurement to control the air-fuel ratio supplied to the engine. The detecting device has two separate gas residence chamber with different diffusion resistance openings for each chamber and separate pairs of electrodes for each chamber whereby the measurement can be separately made in each chamber. The particular chamber selected for measurement may be done on the basis of whether the air-fuel ratio is lean or rich whereby a substantially linear reading results for all ratios or on the basis of the transition-state or steady-state operating condition of the engine to provide either more rapid or more accurate readings.

Abstract: A method for controlling an oxygen concentration sensor for controlling an internal combustion engine, having a sensor body including a wall of oxygen ion conductive solid electrolyte member, and a heater element for heating the wall of oxygen ion conductive solid electrolyte member. During a time period after the ignition switch of the internal combustion engine is turned on, current value of the heater current to the heater element is reduced to a value which is smaller than the current value of the heater current to be supplied after the lapse of the time period.

Abstract: A system of abnormality detection for an oxygen concentration sensor employed to sense the oxygen concentration in engine exhaust gas, for obtaining data to control the air/fuel ratio of a fuel mixture supplied to the engine, the oxygen concentration sensor including a sensor cell element and an oxygen pump element. The system serves to detect an abnormality such as an open-circuit or a short-circuit in electrode connecting leads of the oxygen pump element, on the basis of a level of the sensed pump current together with an air/fuel ratio compensation value which is derived from a sensed oxygen concentration level.

Abstract: An air/fuel ratio control system for an internal combustion engine includes an oxygen concentration sensor for producing an output signal to indicate the concentration of oxygen in the engine exhaust gases, and a circuit for producing a discrimination signal which expresses the inherent error, due to manufacturing deviations, in the output signal of the oxygen concentration sensor. Compensation of the output signal from the oxygen concentration sensor is performed in accordance with the discrimination signal, to produce a compensated output signal which controls means for adjusting the air/fuel ratio of the mixture supplied to the engine. Accurate control of the air/fuel ratio is thereby achieved, irrespective of differences in the operating characteristics of oxygen concentration sensors due to manufacturing deviations.

Abstract: A method of engine air/fuel ratio control using an oxygen concentration sensor producing a concentration-proportional output, in which a compensation value is computed for compensating a basic value such as a basic fuel injection time interval, and in which a deviation of an air/fuel ratio detected using the oxygen concentration sensor from a target air/fuel ratio is measured the compensation value is computed and updated only under the condition that the deviation is below a predetermined value, with the compensation value being determined in accordance with the amount of deviation.

Abstract: An oxygen concentration sensor having an oxygen ion conductive solid electrolyte member forming a gas diffusion restricted region into which a measuring gas is introduced, includes a pump current source for supplying a pump current across a pair of electrodes sandwiching the solid electrolyte through a current detection element and a heater for heating the solid electrolyte. By an arrangement in which the current detection element is connected to one of the pair of electrodes facing the gas diffusion restricted region, error of measurement due to leakage of a drive current of the heater is prevented.

Abstract: Abnormalities are detected in an oxygen concentration sensor employed to sense the oxygen concentration in engine exhaust gas for obtaining data to control the air/fuel ratio of a fuel mixture supplied to the engine, in which the oxygen concentration sensor includes a sensor cell element and an oxygen pump element. The method functions to detect an abnormality of the oxygen concentration sensor on the basis of the value of sensor voltage which is developed by the sensor cell element and at least one of a set of parameters consisting of an engine operating condition, the value of pump current which flows between the electrodes of the oxygen pump element, and an air/fuel ratio compensation value which is derived from a sensed oxygen concentration level.

Abstract: An oxygen concentration detection device having a pair of oxygen pump units includes an oxygen-ion conductive solid electrolyte member a surface of which faces a gas retaining chamber. A measuring gas is introduced through a gas restricted region into the gas retaining chamber. The solid electrolyte member is provided with two pairs of electrodes respectively supplied with a pair of pump currents generated by a current supply circuit. The magnitude of the pump current flowing between the electrodes of one of two pairs of electrodes is controlled so that the voltage difference across the electrodes of the other one of the two pairs of electrodes is maintained at a level corresponding to a reference level. The oxygen concentration in the gas retaining chamber is detected in terms of a sum value of pump currents flowing through the two pairs of electrodes.

Abstract: A method of air/fuel ratio control for a multicylinder internal combustion engine, utilziing an oxygen concentration sensor which produces an output varying in proportion to oxygen concentration, in which compensation values are computed and stored for use in compensating errors of a basic value which controls the air/fuel ratio. While the engine is operating in a condition condition in which the deviation of a detected air/fuel ratio from a target air/fuel ratio is below a predetermined level, respective compensation values are computed and updated for the individual cylinders of the engine, with these compensation values being computed in accordance with variations in the magnitude of the detected air/fuel ratio.

Abstract: Compensation of an output from an oxygen concentration sensor of an air/fuel ratio control apparatus for an internal combustion engine is executed during engine warm-up, to correct for an erroneous component in the oxygen concentration sensor output data caused by incomplete combustion during warm-up. The degree of compensation applied is determined by the engine operating temperature, as represented by the cooling water temperature. Excessive richness of the air/fuel ratio of the mixture supplied to the engine during warm-up is thereby eliminated.