| 摘要 |
A method and apparatus for the remote or non contact sensing or detection of movement of objects and the direction in which they move. Light from a laser diode D is focused by lens system S and directed onto object 1. Light reflected by the object 1 is collected by lens system 13 onto photocell 14. The resulting output from the photocell 14 is fed to digital processor 15 which converts the signal into a wave form (16, Fig.7). The wave form is representative of the directional movement of the object on its linear path. This wave form is transposed onto a reference grid pattern (17, Fig.7) so that the movement of the object on its linear path at any given time may be determined in relation to the observed points of interception of the gridlines on the transposed wave form (A, B, C, Fig.8). The present invention is able remotely to determine whether a product has been moved forward or in a reverse direction. This information may be introduced into an optical/laser Doppler length measuring system. The invention is applicable to the manufacture of elongated products such as wires, cables, rolls and sheeting. |
