| 摘要 |
PURPOSE: To reduce hindrance caused by infrared tissue by providing a modulator that performs substantial square-wave modulation of the amplitude of a high frequency current with a means for gradually increasing the speed at which the amplitude of the high frequency current decreases at the end of a square wave. CONSTITUTION: A switching means 1 produces a high frequency current from a supply voltage, and a modulator II performs substantial square-wave modulation of the amplitude of the high frequency current having a modulation frequency (f), and has a means N for gradually increasing the speed at which the amplitude of the high frequency current decreases at the end of a square wave. When input terminals K1, K2 are connected to a supply voltage source, the means I produces a high frequency current which is modulated into a substantially square waveform by the modulator II having the modulation frequency (f). A gradual increase at the end of the square wave in the speed at which the amplitude of the high frequency current decreases is caused by the means. N. As a result, the presence of an acute angle at the square waveform is avoided, and the degree of hindrance by infrared tissue produced from a lamp IV can be reduced. |
