Patent ID: 6956661
Filing Date: 2005-10-18
Classification: G01B

Abstract:
1. Device for measuring external and internal dimensions of and distances between measurement objects, the device comprising: a) at least one light source and at least one device for generating a parallel pencil of rays from the light beams of the light source; b) at least one slit diaphragm that can be illuminated by the parallel pencil of light rays; c) at least one disc disposed in front of or behind the slit diaphragm, in which the slit diaphragm and the disc can move in relation to each other about a common axis, in particular can rotate, said disc having a spiral slot that intersects the slit of the slit diaphragm, the slit having the form of an Archimedean spiral that obeys the equation r=c·Δφ, where r is the radius of the spiral, c is the quotient of the light beam or light spot scanning speed V d) at least one photoelectric device onto which the light beams passing through the hole aperture and scanning the measurement object are directed, the measurement object being disposed after the hole aperture when viewed in the direction of the light beam; e) an evaluation device, which is connected in series with the photoelectric device and measures the time in which the light beams scan the measurement object/objects, and from the measured times determines the external and internal dimensions and distances between measurement object or measurement objects, said dimensions and distances being proportional to these times; f) there are formed in the slit diaphragm, in front of the spirally slotted disc viewed in the direction of the beam, several slits that are disposed radially around axis of rotation and there is provided for the slits a common light source or there is provided for each slit a separate light source emitting light having one wavelength or light with different wavelengths or light with one wavelength with different frequency modulated light amplitudes; g) there are provided optical contrivances, which deflect the scanning light beams passing through the hole diaphragms into a common beam plane; and h) there are provided optical contrivances, which separate the scanning light beams scanning the measurement object in the time interval T/m (T=duration of a rotation of the spirally slotted disc, m=number of slits) according to wavelength and direct the scanning light beams onto wavelength sensitive photodiodes, the output signals of which produced in the time interval T/m and being proportional to the shade times t i) there is provided a photodiode onto which the scanning light beams scanning the measurement object within time interval T/m (T=duration of a rotation of the spirally slotted disc, m=number of slits) with frequency modulated amplitudes are focussed and whose superimposed frequency modulated photodiode currents are fed to frequency filters and low pass filters of the evaluation device for separation of the scanning light flux associated with the generating system so that the signals which are proportional to the shade times t