Abstract: A bit slice multiplication circuit operating to slice a multiplier, produce products for the sliced multipliers and a multiplicand and sum the products to obtain the multiplication result. The circuit includes a slicing unit for slicing the multiplicand, multiplying units corresponding in number to the number of sliced multiplicands, and adding units provided in correspondence to the multiplying units and implementing summation for multiplication results from corresponding multiplying units while shifting the sliced portions of the multiplicand at each multiplying operation for sliced multipliers and multiplicands by the multiplying units, the multiplication result being obtained by summing all summation results produced by the adding units.

Abstract: A plurality of picture data storage/retrieval apparatuses are connected to each other through a communication line. Each picture data storage/retrieval apparatus has a two-dimensional scanning device for inputting picture data, a keyboard for entering control data, an optical disk for storing the picture data input through the two-dimensional scanning device, a floppy disk for storing a control program, a CRT display device for displaying the picture data stored in the optical disk, a printer for producing a hard copy of the picture data stored in the optical disk, and a communication control unit. When a given apparatus desires registration, retrieval or deletion of picture data in another apparatus, a control unit of the given apparatus communicates with the another apparatus through the communication control units.

Abstract: A steering system for rear wheels of a motor vehicle is provided with a motor for changing the steering angle of the rear wheels and an electric control unit. The control unit produces a desired steering angle signal dependent on the speed of the vehicle and compares the actual steering angle of the rear wheels with the desired steering angle signal. A control signal dependent on the result of the comparison is applied to a driver which drives the motor so that the steering angle of the rear wheels coincides with the desired steering angle.

Abstract: An image information filing apparatus having a first storing medium with a finish data area. A recognition code is previously stored in the first storing medium. After the recognition code of the first storing medium has been written into a second data storing medium, finish data is written into the finish data area of the first storing medium. Both the finish data written into the first storing medium and the recognition code written into the second storing medium allow a one-to-one correspondence between the first and second storing mediums.

Abstract: Title information, which contains management information representing the kind or class of document information be recorded and index information representing the title and recording position of each document information, is provided for the recording and retrieving of the document information. When recording document information, title information is reproduced from an index information recording track of a magnetic tape and written in a title memory. A CPU executes an auxiliary decision as to if the management information of the reproduced title information corresponds to any of various management information preliminarily memorized, a first decision as to if the management information of document information newly applied from a keyboard corresponds to the various management information, and a second decision as to if the title applied from the keyboard coincides with a title in the title memory.

Abstract: There is disclosed a current type inverter excellent in transient response which comprises a two-phase sine wave generator for receiving signals corresponding to a motor speed signal and a speed deviation signal, to provide sine waves shifted 90.degree. in phase, and a vector calculating circuit for calculating stator current instruction vectors from exciting current components and torque current components, the outputs of the vector calculating circuit being applied as frequency instruction signals of a conventional current type inverter.

Abstract: In a speed detector having a fixed frequency oscillator for producing two-phase sine waves to excite two-phase exciting windings of a resolver, first and second multipliers for multiplying the output of the detecting winding of the resolver by the two-phase sine waves respectively, and a position conversion circuit and speed conversion circuit, the speed conversion circuit comprises: a third multiplier for multiplying a signal of the first multiplier by a signal of a VFO; and a fourth multiplier for multiplying a signal of the second multiplier by a signal of the VFO, the outputs of the third and fourth multipliers being applied through a comparator to a proportional integration amplifier, the output of which is used as the rotation speed signal and applied to the VFO, thereby to eliminate the necessity for provision of a countermeasure against harmonics and harmonic noise involved in the use of an integration circuit required when a resolver is used as a detector.

Abstract: In a control device of an AC motor wherein a torque equivalent to that of a DC motor is created by controlling the instantaneous values of its stator current, or in a vector control device, signals from a position detector such as a resolver coupled to the AC motor are utilized to form stator current instruction signals and to provide rotation position feed-back signals and rotation speed feed-back signals for the AC motor, thereby to perform precise servo-control.

Abstract: In a control device of an AC motor wherein a torque equivalent to that of a DC motor is created by controlling the instantaneous values of its stator current, or in a vector control device, signals from a position detector such as a resolver coupled to the AC motor are utilized to form stator current instruction signals and to provide rotation position feed-back signals and rotation speed feed-back signals for the AC motor, thereby to perform precise servo-control.