Abstract: A light source arrangement for a battery-powered light source unit of an endoscope comprises a cylindrical housing, a base disposed at one end of the housing, a plurality of LEDs connected to a flexible circuit board supported on the base and a focusing lens. A light guide for directing light emanating from the LEDs. The light guide comprises a reflective surface formed on an inner wall of the housing, a reflector having a concave reflective surface which is disposed at one end of the housing so as to surround the LEDs or a micro-lens array disposed in front of the LEDs with each micro lens aligned with the LED.

Abstract: A light source device for an endoscope provided with a noncircular opening which is capable of stabilizing the rate of change of the quantity of illuminating light with the quantity of movement of the stop blade and thereby preventing the hunting phenomenon of the stop blade in close-up or the like. The device comprises: a gate portion with a noncircular opening for linearly changing the quantity of light from the light source formed therein; a stop blade for controlling the quantity of light passing through the noncircular opening of the gate portion; and a motor for driving the stop blade. The noncircular opening has two V-shaped portions having different opening angles. The stop blade is provided with a circular auxiliary opening for passing part of the light therethrough.

Abstract: The present invention relates to a plasma processing apparatus capable of obtaining a satisfactory plasma arc and a processing method used by this plasma processing apparatus.The plasma processing apparatus is constructed to vary an electric current or a voltage during start up at a fixed period for a fixed time. The plasma processing apparatus has a plasma power source capable of controlling an electric current or a voltage applied to a plasma torch, and an electrode and a nozzle are communicated by means of an electrification in the plasma torch.In a method for performing a plasma process by a plasma processing apparatus, a mixing gas has a ratio of Hydrogen to Argon in a range from 5 to 20 Vol %, and a frequency of a plasma electric current is controlled in a range from 10 to 30 KHz.