Katsuo Mohri

Microcomputer Control for Sensorless Brushless Motor

The microcomputer control of a brushless motor without a shaft position sensor is studied. A method which permits the determination of the permanent magnet rotor position by the back electromotive force (EMF) induced in the stator windings and the starting technique which uses the motor as a synchronous motor at standstill are explained. The motor voltage is chopped by commutator transistors to change the motor speed. The control system consists of a 4-b single-chip microcomputer and two quad-comparators.

A High-Definition MUSE VCR with Analog Segment Recording Method

A high-definition VCR-MUSE VCR-has been developed along with the other high-definition TV components such as a MUSE-TV signal reception unit, a wide screen color display, and a video disc player.

Video and sound signal recording and reproducing device

A sound signal recording and reproducing device for use in a picture signal recording and reproducing apparatus comprises a first sound signal recording and reproducing system recording a sound signal in superposed relation with a picture signal on the same track on a magnetic tape by a rotary head, and a second sound signal recording and reproducing system capable of recording a sound signal independently of the picture signal by a stationary head in a direction parallel with the traveling direction of the magnetic tape.

Microprocessor Controlled Variable Play-Back Speed System for Video Tape Recorder

A new home use video tape recorder with features of varying play-back speed is required for further attractive application of VTR especially in the field of sports, such as in training and form correction.

A New Concept of Handy Video Recording Camera

High density recording technology is going to realize the very compact VCR system. And all solid state color video camera which has many advantages over conventioal tube type cameras, e. g. light-weight, low power consumption, high reliability, lag elimination and high picture quality, has been developed.1) The authors have developed a handy video recording camera-the MAG CAMERA, which is shown in Fig. 1. This camera features two newly developed technologies; high density two hour recording system and all solid state color camera with single-chip MOS imager. The combination of above two technologies realized the unprecedented performance with compactness and handiness comparable to 8 mm movie cameras.

The FM Audio Signal Recording System for 8 mm Video

The 8 mm Video standard was determined by the Working Groups in 8 mm Video Conference which is composed of tuany companies in the world in March, 1983. The 8 mm Video system aims to achieve a small-sized & light-weighted design, a good quality picture and a high quality sound. Metal head and metal powder( MP)/evaporated(ME) tape improve a recording density and realize a compact cassette-tape & a small cylinder mechanism.

Design Philosophy and Practice of Microprocessor-Controlled Room Air Conditioner

Electrical home appliances go electronic rapidly these days. Figure 1 shows needs for a room air-conditioner to be. met by electronic control techniques ; seeds. The needs include power saving, comfortableness, low noise, improved function, operatability, and reliability. With the conventional mechanical control system, it is difficult to improve the comfortableness and operatability, and therefore, emphasis has been laid mainly on improvement of power consumption and noise characteristics. In contrast to this, an electronic control introduced to a room airconditioner can easily realize the following advantages: comfortableness due to finer thennostatic setting, operatability through feather touch operation and remote control, and reliability by a motor lock protection circuit. To get the maximum effect from a room air-conditioner equipped with an electronic control, the authors gave much thought to optimum daily and yearly room airconditioner operating patterns. With them, overcooling and overheating can be prevented, leading to simultaneous realization of power saving and healthy comfortableness. Such control is beyond the reach of the mechanical system, and this is an area where microprocessor control is most effective.

Chroma Systems Trend in the Past and Future and Latest Chroma IC with Versatile Flexibility

Chroma circuit is one of the most important parts in a color television set. Figure 1 shows the history of chroma systems focusing the change of active devices and the quantity of parts.s

A Receiver for Experimental Still-Picture TV System

静止画実験システムの受信機を開発した。静止画実験信号は, 映像, 音声および同期の時分割多重に大幅なディジタル信号を採用している.この受信機において, ディジタル同期信号と, 4値PCM音声信号の再生および制御信号抽出のために高度なディジタルプロセスを開発し, 静止画の再生には磁気ディスクフレームメモリーを採用した.番組受信実験を行い, 同期安定限界S/N : 6dB, 同期引込時間 : 5ms, 解像度 : 230本, S/N : 43dBの結果をえた.本論文では, 高周波部を除くベースバンド部について述べる.