Abstract: To provide an inexpensive printer that suppresses the occurrence of paper jams. A printer includes: a platen roller configured to feed linerless label paper having an adhesive surface on a side opposite to a printing surface on which printing is to be performed, the adhesive surface being coated with an adhesive; a print head configured to perform printing on the linerless label paper being fed by the platen roller; and a cutting device having a fixed blade and a movable blade. The movable blade 621 advances from the adhesive surface side of the linerless label paper toward the fixed blade, and a surface of the movable blade on a downstream side in a paper feed direction faces a surface of the fixed blade on an upstream side in the paper feed direction.

Abstract: In a schlieren optical system, a laser beam is passed through the jet flow and the ambient around the jet flow, and a high speed sampling is performed using a high speed photo sensor while displacing measurement points. The value obtained by sampling represents a result of the optical path caused curved by a density gradient generated in an arc-shape from the center of the jet flow. The value is subjected to a high speed discrete Fourier transform and decomposed into frequency components which constitute the noise. Thereafter, Abel inversion is performed on data belonging to a particular frequency to obtain a density gradient in the radial direction from the center of the jet flow. The obtained density gradient is visualized in a graph display, so that the position of the sound source and the state of the jet flow can be accurately grasped.

Abstract: In a schlieren optical system, a laser beam is passed through the jet flow and the ambient around the jet flow, and a high speed sampling is performed using a high speed photo sensor while displacing measurement points. The value obtained by sampling represents a result of the optical path caused curved by a density gradient generated in an arc-shape from the center of the jet flow. The value is subjected to a high speed discrete Fourier transform and decomposed into frequency components which constitute the noise. Thereafter, Abel inversion is performed on data belonging to a particular frequency to obtain a density gradient in the radial direction from the center of the jet flow. The obtained density gradient is visualized in a graph display, so that the position of the sound source and the state of the jet flow can be accurately grasped.