In manufacturing processes, various and suitable pulse shapes are required for the purpose of materials processing, and the pulse shape is regarded as a dominant factor according to the specific property of materials. Therefore, this study has undertaken to generate the correct ones by using the two-pulse superposition technique. The pulsed Nd:YAG laser using a multi-mesh inductor L and capacitor C network and the pulse superposition technique is described. We have tried to superpose two pulses with the single shot multivibrator (SSM: 74LS123) having two silicon-controlled rectifiers (SCRs) which control the delay time of the two gate turn-on signals. One is a main rectangular pulse, and the other is a superposed sinusoidal pulse. The use of this technique might impart a number of advantages to people who need a suitable pulse shape for particular applications such as welding, cutting, and drilling. In addition, we compared the case of no superposition and applied input energy of 100 J in only the main circuit with that of superposition and applied input energy of 75 J in the main circuit and 25 J in the superposing circuit. It is found that the maximum efficiency of 4.5% is obtained within the range of delay time less than 230 s by adjusting the delay time from 0 to 1 ms. © 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98) Subject terms: materials processing; pulsed Nd:YAG laser; multi-mesh inductor L and capacitor C; pulse superposition technique; suitable pulse shape.

We demonstrate a simple pulsed CO2 laser with long pulse duration of millisecond order in a tube at a low pressure of less than 30 Torr. The power supply for our laser system switches the voltage of the ac power line (60 Hz) directly. The power supply does not need elements such as a rectifier bridge, energy-storage capacitors, or a current-limiting resistor in the discharge circuit. In order to control the laser output power, the pulse repetition rate is adjusted up to 60 Hz and the firing angle of the silicon controlled rectifier (SCR) gate is varied from 30° to 150°. The maximum laser output of 35 W is obtained at a total pressure of 18 Torr, a pulse repetition rate of 60 Hz, and a SCR gate firing angle of 90°. In addition, the resulting laser pulse width is approximately 3 ms (full width at half maximum). This is a relatively long pulse width, compared with other repetitively pulsed CO2 lasers.

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Korea Institute of Intellectual Property Korean Intellectual Society 73 ratio and acceptance ratio for the cases in KIPT, the Patent Court of Korea and the Supreme Court of Korea can be used as the standard index for partly anticipating the acceptance or dismiss results of their disputes to ordinary people as well as the interested persons related with various patent disputes.