Abstract: A system and method for detecting defects in a material in a liquid bath, the system including a light that illuminates the material through the liquid bath, at least one camera with a view of the material through the liquid bath, and a digital processor in communication with the at least one camera. The at least one camera transmits image data to the digital processor and the digital processor analyzes the image data to identify defects in the material. In an embodiment of the invention, the system includes an anti-turbulence interface through which the at least one camera views the material.

Abstract: An optical inspection system mounts on a cigarette making machine or like system and detects the presence of bands having irregular widths or spacings. In response to the detection of irregular bands, the optical inspection system instructs the cigarette making machine to reject cigarettes which will be subsequently made from portions of the cigarette paper containing the irregular bands. The optical inspection system includes a sensor which can accommodate different types of cigarette paper and band material having varying reflectance properties. In operation, sensor circuitry detects the range of voltages produced by a sensor detector, and formulates a peak value (or average peak value) for the range of voltages. The circuitry then takes a percentage of this peak value to form a threshold value. This threshold value is compared with the AC signal from the sensor detector. If the AC signal exceeds the threshold, then the circuitry asserts a signal to indicate that a band is present.