Abstract: The liquid crystal is written with a laser beam. The laser beam generated by a laser source is applied through an optical control unit such as galvanometer mirrors to the liquid crystal. The intensity of the laser beam applied to the liquid crystal is controlled by a laser beam intensity varying unit. A writing control unit controls the mechanical displacement caused by the optical axis control unit and controls the laser beam intensity varying unit. The laser beam energy applied to the liquid crystal can be maintained constant, thus enabling a constant written line width even during acceleration and deceleration of the optical axis control unit.

Abstract: The liquid crystal is written with a laser beam. The laser beam generated by a laser source is applied through an optical control unit such as galvanometer mirrors to the liquid crystal. The intensity of the laser beam applied to the liquid crystal is controlled by a laser beam intensity varying unit. A writing control unit controls the mechanical displacement caused by the optical axis control unit and controls the laser beam intensity varying unit. The laser beam energy applied to the liquid crystal can be maintained constant, thus enabling a constant written line width even during acceleration and deceleration of the optical axis control unit.

Abstract: A modulating wave signal whose phase abruptly changes is compared with a carrier signal to generate a pulse width modulation pulse. The carrier signal is a sine wave signal having a frequency n times as high as that of the modulating signal and synchronized with the modulating signal. A phase of the carrier abruptly changes by a factor of n as the phase of the modulating signal abruptly changes. Thus, a pulse with modulation pulse which causes an output voltage of a pulse with modulation inverter to be sinusoidal is generated even if the phase of the modulating wave signal abruptly changes.

Abstract: A control apparatus for a thyristor converter which supplies electric power to a load generating a changeable electromotive force, wherein, in response to a load current being changed from an intermittent load current mode to a continuous load current mode, an actual main circuit constant of the load is calculated on the basis of a pregiven main circuit constant of said load, a predetermined minimum value of a DC average motor current at which a compensation control angle is zero, a DC average load current and a set control angle at a time when the load current just changed from the intermittent load current mode to the continuous load current mode.The compensation control angle is obtained on the basis of the calculated actual main circuit constant and the DC average load current.The calculated compensation control angle is added to the set control angle to thereby apply the added angle to the thyristor converter as a firing control angle.

Abstract: Disclosed is a signal transmitting and receiving apparatus for transmitting and receiving parallel-by-word data signals, converting the parallel-by-word data signal to serial-by-word data signal, and transmitting the serial-by-word data signal to control units connected in a multi-drop connection configuration or receiving the signals transmitted from the control units.An external control mode and an internal control mode in receiving the parallel-by-word data signal, a simulation mode, and the prevention of competing status between a write timing of the parallel-by-word data to a buffer memory and a read timing of the data for converting it to serial-by-word data are described.