| 摘要 |
PROBLEM TO BE SOLVED: To measure the tension of a web with high accuracy, not depending on the kind of the web, and to measure the speed of the web simultaneously at a low cost. SOLUTION: The device for measuring the tension and the speed includes a semiconductor laser 1 which emits laser light to the web 11 being an object in conveyance by a conveying device, a laser driver 4 which makes the semiconductor laser 1 operate so that at least one of a first oscillation period wherein an oscillation wavelength increases and a second oscillation period wherein the oscillation wavelength decreases may be present repeatedly, a photodiode 2 and a current-voltage conversion amplification part 5 which detect an electric signal containing an interference waveform produced by a self-bonding effect of the laser light emitted from the semiconductor laser 1 and return light from the web 11, a signal extracting part 7 which counts the number of the interference waveforms contained in an output of the current-voltage conversion amplification part 5, and an arithmetic part 8 which calculates the speed and the tension of the web 11 on the basis of the result of counting of the signal extracting part 7. COPYRIGHT: (C)2011,JPO&INPIT |
