Abstract: A surface of copper foil wound onto a guide roller 26 is irradiated with light. Specular light from the copper foil surface is received by CCD cameras 14a, and scattered light from the copper foil surface is received by CCD cameras 14b. When, in a region in which the amount of specular light received by the CCD cameras 14a is equal to or larger than a first threshold, a portion having a luminance equal to or larger than a second threshold is present, and when the amount of scattered light received by the CCD cameras 14b is smaller than a luminance average, that region is determined to be a defective copper portion.

Abstract: A line illuminating apparatus comprises a pair of irradiating units 12a, 12b of the same structure. The irradiating unit 12a. The light irradiating unit 12a includes a light source 14a, a first light guide 16a consisting of a large number of optical fibers, a light connector 18a, and three second light guides 20 (20a to 20c). The first light guide 16a permits the light emitted from the light source 14a to be incident as a slender rectangular light ray on the light connector 18a. The light emitted from the light connector 18a is divided by the three second light guides 20. Each light guide 20 is in the form of a thin plate, and the light emitting surfaces of the light guides 20a to 20f are arranged to define a imaginary semicylindrical plane surrounding the irradiating line L of work 28. The particular construction is effective for suppressing the loss of energy required for illumination. Also, the inspection is not adversely affected by the presence of, for example, an irregularity on the surface of the work.

Abstract: In the case that an analog signal is recorded or reproduced by using a sensor and recording medium relatively moving against the sensor, a sampling signal is generated which is adapted to have a frequency thereof deviated dependently upon an amount of wow and flutter caused by fluctuations in the speed of the relative motion therebetween. A reproduced signal is sampled by means of the sampling signal and, a sampled signal is stored in a memory. After this, a stored contents in the memory are read out by using a reading signal with a predetermined frequency, thereby to remove from the reproduced signal varying frequency components caused by the wow and flutter.

Abstract: A flame sensor according to the invention enables automatic monitoring and/or control of the condition of combustion of a flame such as perfect combustion or imperfect combustion by detection of particular infra-red radiations emitted by the flame. The flame sensor includes a rotary disc having two sets of band-pass filters mounted thereon, a single photoelectric conversion device for measuring intensity of radiations having passed said band-pass filters and a division circuit for providing a ratio of an output of the photoelectric conversion device containing the wavelength of a resonant radiation of a carbon dioxide to an output of the photoelectric conversion device containing no such wavelength.