摘要:
A three-dimensional measurement method and device are intended for fast and accurate measurement of large objects such as vehicles. The method includes the steps of determining approximate measurement positions of a shape measurement sensor; positioning the sensor at successive approximate measurement positions to read off the shape of surface portions of the object represented by points on the object whose co-ordinates are expressed in a system of axes fixed relative to the sensor; identifying accurate positions of the sensor at the approximate measurement positions relative to a predetermined fixed system of axes; and converting the co-ordinates of the points of the surface portions expressed in the system of axes fixed relative to the sensor into co-ordinates expressed in the fixed system of axes on the basis of the identified accurate positions of the sensor.
摘要:
The invention can be used to determine the color to be given to a dental prosthesis, for example, on the basis of color measurements performed on adjacent teeth in the mouth of the patient. An optical fiber instrument picks up light reflected from a tooth and transmits it to the inlet of a spectrocolorimeter which associated with a microprocessor in order to determine the diffuse spectral reflectance of the tooth and to calculate the tristimulus values of its apparent color under various different types of illumination. The invention is particularly suitable for determining the color of dental prostheses.
摘要:
A spectrum modulation encoding sensor subjected to the physical magnitude to be measured is connected by an optical fiber to a source of incoherent light, and by an optical fiber to a static demodulation system comprising a set of birefringent elements producing a birefringence gradient along a privileged optical direction x; the system demodulates the signal provided by the sensor optically by means of a Fourier transform.
摘要:
The optoelectronic method and system provides for remote detection of physical magnitudes by multiplexing and demultiplexing signals from a plurality of sensors. The system utilizes a single source of incoherent light which illuminates via optical fibers a plurality of sensors associated with encoding devices. Periodic modulation on the light transmitted by each sensor is accomplished at a frequency which is characteristic of the sensor in question. Demultiplexing is provided for demodulating the signals from the various sensors by a Fourier transform, and for identifying each signal by its characteristic modulation frequency.
摘要:
An optical device (12) includes a front surface located on the side of the sample to be observed and a rear surface oriented towards the elements for acquiring (18, 19) an image or a user. It further includes a combination of four aligned lenses. The lenses are arranged in the following sequence from the front rearwards: a plano-convex lens (28), a convexo-concave lens (30), a plano-concave lens (32) and a biconvex lens (34). The plano-concave (32) and the plano-convex lenses are respectively such that they each have a substantially planar surface and a concave surface or convex surface respectively. The invention is applicable to a cell analyzer.
摘要:
The invention relates to an optical sensor using spectrum modulation encoding and operating by reflection, the sensor is connected by an optical fiber (10) to a light source and to a demodulator, and it comprises a collimator lens (16), a first polarizer (18), a sensitive component (20) subjected to the physical magnitude to be measured, a second polarizer (32), and catadioptric reflection means (28) such as a corner of a cube. The sensor of the invention enables all of the light flux to be reinserted into the optical fiber (10) after passing through the sensor without any disturbance from interference phenomena.
摘要:
An optoelectronic apparatus for the remote measuring of a physical magnitude which comprises two light sources emitting luminous fluxes centered on two different wavelengths and means for controlling the alternate operation of these light sources. A sensor is provided for receiving the luminous flux emitted by the respective light sources and causing a periodic spectral modulation of the luminous flux a frequency depending on the value of the physical magnitude to be measured. An analysis means is provided for analyzing the luminous flux transmitted by the sensor, the analysis means being of the static type and including a birefringent element which is tuned to the sensor and produces an optical path difference close to that produced by the sensor.
摘要:
Apparatus for allowing the photoactivation of photosensitive composites used especially in the dental field: A case containing a power supply unit electrically controlled by a central electronic processing unit. A light source connected to the supply unit and which is formed by a plurality of light-emitting diodes. The diodes are associated with a concentrating device making it possible to concentrate in an optimal manner, at a given point, the light emanating from all the emissive areas of the diodes. The concentrating device includes a respective optical fiber associated with each light emitting diode.
摘要:
A sequential demultiplexing receiver for a network of sensors (20) using spectrum modulation encoding, the receiver being essentially constituted by an integrated optical circuit comprising a substrate (34) that is birefringent or semiconductive on which there are formed mode couplers or mode converters (38) operating by the electro-optical effect and that are sequentially activated at high frequency to generate optical path length differences matching those of the sensors.
摘要:
The sensor for detecting and measuring the angle of rotation of the polarization plane of light delivered by a sensitive system (19) subjected to an external phenomenon such as a magnetic field, for example, with the sensor being connected via an optical fiber (18) to a source of incoherent light (10) and essentially comprising the sensitive system (19), a quarterwave plate (22), a birefringent crystal (24), and an analyzer (26). The light flux provided by the sensor is spectrally modulated as a function of the angle of rotation of the plane of polarization of the light delivered by the above-mentioned system (19).