TAYLOR HOBSON LIMITED Patent applications |
Patent application number | Title | Published |
20150025845 | SURFACE MEASUREMENT APPARATUS AND METHOD - A stylus is deflected as a tip of the stylus follows surface variations along a measurement path on a surface of a workpiece. A transducer provides measurement data in a measurement coordinate system. A data processor is configured to: determine a relationship between the data in the measurement coordinate system and nominal surface data representing the expected surface characteristic of the workpiece in a workpiece coordinate system; simulate a measurement data set for the nominal surface using the nominal surface data and the determined relationship; if a simulated range of the simulated data set does not meet a given criterion, adjust a selected measurement data value for a selected point and repeat the simulation to determine an adjusted data value for which the simulated range meets the criterion; and determine start conditions required for a measurement procedure to provide the adjusted data value for the selected measurement point. | 01-22-2015 |
20150012245 | MEASUREMENT APPARATUS AND METHOD - A computer implemented method of determining the surface shape of an aspheric object using a metrological apparatus includes positioning the object on a support surface of a turntable so that an axis of the object is tilted with respect to the axis of rotation of the turntable; using a measurement probe to make a first measurement of the object; rotating the turntable; after rotation of the turntable, using a measurement probe to make a second measurement of the object, diametrically opposite the first measurement, estimating a first angle based on fitting the first measurement data using a surface model including: a dependency on the axis tilt angle and a dependency on the radius of the base of the object; estimating a second angle based on fitting the second measurement data to the surface model; and determining the tilt angle based on the first angle and the second angle. | 01-08-2015 |
20140347660 | METROLOGICAL APPARATUS - Metrological apparatus and a confocal sensor for use in such apparatus are described. The confocal sensor ( | 11-27-2014 |
20140343893 | METROLOGICAL APPARATUS AND A METHOD OF DETERMINING A SURFACE CHARACTERISTIC OR CHARACTERISTICS - A metrological apparatus has a surface data determiner to determine from measurement data a measured surface roughness data set ( | 11-20-2014 |
20130054194 | SURFACE MEASUREMENT INSTRUMENT AND CALIBRATION THEREOF - A method of calibrating a surface measurement instrument includes rotating a work piece having an undulating surface on a turntable of a metrological apparatus; measuring the surface of the work piece at a plurality of rotational positions; analysing the results of the measurement to determine parameters describing an error causing characteristic of the metrological apparatus; and using the determined parameters to correct measurement data for the error causing characteristic of the metrological apparatus. | 02-28-2013 |
20120278035 | SURFACE MEASUREMENT INSTRUMENT AND METHOD - A method of characterising the surface of an aspheric diffractive structure includes using a metrological apparatus to perform a measurement on the surface of the structure so as to provide a measurement profile representing the z-direction deviations of the surface of the structure; determining parameters relating to the aspheric and diffractive components of the aspheric diffractive structure; producing data having the determined parameters; and comparing the produced data with the measurement profile to determine residual error data. | 11-01-2012 |
20120176624 | APPARATUS FOR AND A METHOD OF DETERMINING SURFACE CHARACTERISTICS - Light reflected by a sample surface region and a reference surface interfere. A detector senses light intensity at intervals during relative movement along a scan path between the sample surface and the reference surface to provide a series of intensity values representing interference fringes. A data processor receives first intensity data comprising a first series of intensity values resulting from a measurement operation on a surface area of a substrate and second intensity data comprising a second series of intensity values resulting from a measurement operation on a surface area of a thin film structure. A gain is determined for each thin film of the thin film structure. Substrate and apparent thin film structure surface characteristics are determined on the basis of the first and second intensity data, respectively. The apparent thin film structure surface characteristic is modified using the substrate surface characteristic and the determined gain or gains. | 07-12-2012 |
20120111124 | METHOD AND APPARATUS FOR DETERMINING PHASE FRACTIONS OF MULTIPHASE FLOWS - A multiphase meter for use in the quantification of the individual phase fractions of a multiphase flow has: a resonant cavity through which, in use, a multiphase fluid flows, a signal generator configured to apply electromagnetic energy at a range of frequencies to the cavity, and an enhancing and/or suppressing facility for enhancing and/or suppressing resonant modes of a signal produced resultant to the application of electromagnetic energy to the cavity. | 05-10-2012 |
20120004888 | APPARATUS FOR AND A METHOD OF DETERMINING SURFACE CHARACTERISTICS - A coherence scanning interferometer carries out: a coherence scanning measurement operation on a surface area using a low numeric aperture objective so that the pitch of the surface structure elements is less that the spread of the point spread function at the surface to obtain structure surface intensity data; and a coherence scanning measurement operation on a non-structure surface area to obtain non-structure surface intensity data. A frequency transform ratio determiner determines a frequency transform ratio related to the ratio between the structure surface intensity data and the non-structure surface intensity data. A structure provider sets that frequency transform ratio equal to an expression representing the electric field at the image plane of the interferometer in terms of surface structure element size (height or depth) and width-to-pitch ratio and derives the surface structure element size and width-to-pitch ratio using the frequency transform ratio. | 01-05-2012 |
20110258867 | SURFACE MEASUREMENT INSTRUMENT AND METHOD - A method of determining a correction parameter for use in effecting alignment of a component of a metrological apparatus in at least one direction is described which includes: positioning an artefact on a support surface of a turntable of the metrological apparatus so that a measurement surface of the artefact is asymmetric with respect to a rotation axis of the turntable in the at least one direction; using a measurement probe of the measurement instrument to make a first measurement of the measurement surface; rotating the turntable; using the measurement probe of the measurement instrument to make a second measurement of the measurement surface after rotation of the turntable; and determining a correction parameter from the first and second measurements. | 10-27-2011 |
20110166823 | SURFACE MEASUREMENT INSTRUMENT - A surface measurement instrument for obtaining surface characteristic data of a sample surface is described. Relative movement between a reference surface and a sample support is caused to occur while a sensor senses light intensity at intervals along a scan path to provide a series of intensity values representing interference fringes produced by a region of a sample surface during said relative movement and from which series of intensity values surface characteristic data can be derived. The sample support is both translatable and tiltable in at least one direction perpendicular to a scan direction so that the sample support can be both tilted to cause the scan path to be normal to the sample surface region and translated to compensate for translation movement due to the tilting. | 07-07-2011 |
20100217561 | METROLOGICAL INSTRUMENT - A metrological instrument determines a surface profile or form of a surface ( | 08-26-2010 |
20100161273 | APPARATUS FOR AND A METHOD OF DETERMINING SURFACE CHARACTERISTICS - A coherence scanning interferometer ( | 06-24-2010 |
20090319225 | APPARATUS FOR AND A METHOD OF DETERMINING SURFACE CHARACTERISTICS - Light from a light source ( | 12-24-2009 |
20090300929 | METROLOGICAL APPARATUS FOR MEASURING SURFACE CHARACTERISTICS - An attitude arm mounted to a support arm is rotatable about a pivot. The attitude arm holds a stylus gauge, which generates a signal representing deflection of the stylus in a measurement direction as the stylus follows a surface of a workpiece rotated on a turntable. An attitude switching mechanism allows switching between a first stylus attitude generally aligned with the turntable spindle axis and a second stylus attitude generally aligned perpendicular to the turntable spindle axis. To enable alignment of the measurement direction with the spindle axis, first and second adjusters enable the stylus tip to be moved perpendicular to the spindle axis and the measurement direction when in the first and second stylus attitudes, respectively. An orientation mechanism is provided to rotate the measurement direction of the stylus. A stylus tilt mechanism is provided to tilt the stylus about a tilt axis parallel with the measurement direction. | 12-10-2009 |
20090012743 | Surface Measurement Instrument - A surface measurement instrument ( | 01-08-2009 |
20080234963 | Calibration of a Metrological Apparatus - A metrological apparatus has a driver ( | 09-25-2008 |
20080215271 | SURFACE PROFILING APPARATUS - Light from a broadband source ( | 09-04-2008 |