Abstract: A controlled atmosphere cutting method and a cutting tool are provided to prevent wear on the cutting tool when cutting is performed on a material for forming an oxide protective film. According to the invention, in a cutting method of supplying gas in an atmosphere of a machining portion to perform cutting when a work piece is cut, gas containing a high concentration of oxygen is supplied as atmospheric gas to bring the machining portion into an oxidized atmosphere, so that an oxide is formed between the cutting edge of a cutting tool 4 and a workpiece and thus a damage and wear are reduced on the tool. The above-mentioned atmospheric gas is oxygen enriched air in which oxygen in the air is condensed, and the atmospheric gas has an oxygen concentration up to 40%, exceeding an oxygen concentration of the air.

Abstract: A controlled atmosphere cutting method and a cutting tool are provided to prevent wear on the cutting tool when cutting is performed on a material for forming an oxide protective film.

Abstract: A system for interconnecting with a single coaxial cable between an image pickup device such as a color television camera and a recording device such as a video tape recorder is provided. The camera signal is separated into the luminance signal which in turn is frequency modulated and two color signals which in turn are converted at a low frequency band lower than the lower sideband of the FM luminance signal. The FM luminance signal and the modulated color signal are multiplexed with the audio signal at the base band and transmitted on a single coaxial cable to the recording device. In the case of the high-density recording without the guard bands between the adjacent tracks, there is provided a means for maintaining the one-to-one correspondence between the rotating recording head and the processing of the modulated color signal which is varied for each track.