| 摘要 |
A web guide apparatus corrects for high frequency oscillations, sometimes referred to as "web weave", of a travelling web. A light-weight movable carriage is mounted to a rigid support structure and is driven by a brushless DC motor having an integral lead screw and low inertia characteristics. The web guide manifests a response bandwidth in excess of 1 Hz. and preferably at least approximately 8 Hz., and a material resonance outside of the response bandwidth. Lateral web position is detected by a web position detection unit that employs a CCD line sensor. The output signal from the web position detection unit is supplied to a control circuit that generates a PWM signal to drive the brushless DC motor. The control circuit also includes adjustable gain stages that are used to compensate for web float and web flutter that occurs during certain operating conditions.
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