Hitachi, Ltd.

Yasuharu Tamuro

Akira Ishibashi

Masanori Ogino

Fumio Inoue

Takashi Yasuhara

Miyuki Ikeda

Hideaki Kobayashi

Kenji Nandoh

Motonobu Hattori

Kunio Ishii

A multi-scan type display apparatus with pointer function includes a multi-scan type display unit for displaying a plurality of kinds of main picture signals having different numbers of scanning lines and a pointer position identifying signal generating circuit for generating a pointer position identifying signal. The pointer position identifying signal generating circuit transfers the pointer position identifying signal to the multi-scan type display unit, the multi-scan type display unit includes a universal vertical position address signal generating circuit, a horizontal position address signal generating circuit, a pointer signal generating circuit and a superimposing circuit. The pointer signal generating circuit generates a pointer signal in response to the pointer position identifying signal, a universal vertical position address signal and a horizontal position address signal, the pointer signal is superimposed on the main picture signal by the superimposing circuit, so that even if the input signal to the multi-scan type display unit is changed over to a different one having a different number of scanning lines, a pointer display position is kept constant on the display unit, and the pointer position can be moved to a desired position by controlling the pointer position identifying signal.

Multi-scan type display system with pointer function

A method and apparatus for controlling an induction motor, in which an AC power source is connected to the induction motor through a switch and a frequency converter, and the motor speed is controlled by controlling the output frequency and output voltage of the frequency converter. In the starting operation, the induction motor in a free-running state is supplied with an initial voltage in a given frequency which is expected to make the absolute value of the motor current minimum or near minimum, and then the supply voltage is increased gradually from the initial voltage with its frequency being retained at the given voltage. When the output frequency of the frequency converter reaches a predetermined value, the output frequency and voltage thereof are increased gradually with the ratio therebetween being maintained at a given value.

Method and apparatus for controlling AC motor

A rotary electrical machine connected to a rotary machine heated to high-temperature, such as a heater roll used for processing fibers, a ventilation fan for ventilating a high-temperature furnace, etc., includes a rotary shaft journaled by bearing means of the rotary electrical machine including a first member formed of material of low thermal conductivity for supporting a rotor, and a second member formed of material of high hardness constituting an output end portion of the rotary shaft remote from the bearing means. The first member and the second member are united together in a position located opposite the rotor with respect to the bearing means and spaced apart from the bearing means. Cooling means, such as a heat dissipating fan, heat dissipating fins, etc., is mounted on a portion of the rotary shaft between the vicinity of the joint of the two members and the bearing means. By this arrangement, a rise in the temperature of the bearing means of the rotary electrical machine can be avoided when the machine is connected to a rotary member of high-temperature, and the rotary member can be connected and disconnected readily and positively.

Rotary electrical machine connected to high-temperature load

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Narashino, Japan

Yasuharu Tamuro