Patent ID: 7663767
Filing Date: 2010-02-16
Classification: G01B

Abstract:
1. An apparatus for measuring an inner radius of a hollow cylinder, comprising: at least a light emitting means for providing a light source with multiple wavelength or a spectrum, the light emitting means including a light emitting component for providing the light source; at least a light dispersing means for receiving light from the light emitting means and respectively focusing rays with different wavelengths in the light source into focal points with different intervals; at least a reflecting component disposed in the centre of an inner circle of the hollow cylinder and within a range of the focal points, for reflecting rays within the range of the focal points to an inner wall of the hollow cylinder and reflecting rays reflected or scattered by the inner wall of the hollow cylinder; at least a wavelength measuring means for measuring wavelengths of the rays reflected by the reflecting component, such that the inner radius of the hollow cylinder is determined from the measured wavelengths of the reflected rays; and a modulating component provided between the wavelength measuring means and the light emitting component, for receiving the rays reflected by the reflecting component and modulating the rays into applicable light beams.