Optics: measuring and testing – Angle measuring or angular axial alignment – Alignment of axes nominally coaxial
Reexamination Certificate
2001-11-29
2003-12-16
Font, Frank G. (Department: 2877)
Optics: measuring and testing
Angle measuring or angular axial alignment
Alignment of axes nominally coaxial
C356S154000
Reexamination Certificate
active
06665064
ABSTRACT:
RELATED APPLICATION DATA
This application claims the benefit of and priority to German Patent Application No. 100 597 28.9 filed Nov. 30, 2000, incorporated herein by reference in its entirety.
BRIEF DESCRIPTION OF THE INVENTION
The invention relates to a device for ascertaining the relative position of bodies or of surface areas of these bodies. The invention is especially suitable for alignment of machines, or successive machines, such as machine trains. The object of the invention is comparable to the one formulated in the PCT Application PCT/EP97/00274, incorporated herein by reference in its entirety.
DESCRIPTION OF RELATED ART
PCT Application PCT/EP97/00274 discloses, known devices of this type have a measurement arrangement which uses at least one light beam emitter and at least one monoaxial or multiaxial optoelectronic position detector. For the sake of brevity, reference is made to the contents of the indicated PCT application, especially its drawings and specifically FIGS. 1 to 3.
PCT/EP97/00274 thus discloses a satisfactory approach to how widening of the area can be achieved essentially using software in position detectors with effective receiving surfaces which are too small for a measurement task.
SUMMARY OF THE INVENTION
In any case, the application of the teaching from the indicated PCT application for especially small (generally with a small area) position detectors leads to the need for relatively frequent manual shifting of the sensor housing; this would, for example, make handling by an operator unreasonably difficult for small sensor types.
An exemplary object of the invention is to make available an alternative approach to the posed problem for widening the area in small-area position detectors which enables essentially simplified handling even for machines which are seriously out of calibration. This approach will allow the use of commercial CCD or CMOS image sensors which do have a very large number of pixels which can be individually resolved, but which are equipped only with an effective surface as small as possible for, for example, lower production costs. Direct use of these economical CCD or CMOS image sensors in a means of the generic type is not practical and therefore requires more extensive measures for their satisfactory applicability.
This object is achieved through an optical widening of the beam path compared to optical beam paths as are used for conventional light beam emitter or position detector combinations.
For example, instead of a conventional impact or target surface for a light beam (preferably laser light beam), a matt disk is used which typically has roughly 2 to roughly 20 times larger linear dimensions than the position detector to be used, and which thus represents a correspondingly larger usable receiving surface. In this way, instead of a measurement surface of 0.5 square centimeters (50 square millimeters) a usable surface of, for example, roughly 2 to 200 square centimeters can easily be made available. This is a major advantage for the alignment of large machines such as turbines or in shipbuilding.
In addition to the indicated matt disk, a projection means is used which images the matt disk by means of an objective lens to scale and conformally onto the position detector to be used, and in doing so undertakes linear reduction by a factor of roughly 2 to 20. It is important to have scattered light portions which are as diffuse as possible reaching the optoelectronic position detector. For this purpose it is advantageous to provide the indicated matt disk with a color-filtering effect. It can be made, for example, as a red filter. In addition, it is useful to protect the matt disk by, for example, visor-like shading devices against incident outside light.
Therefore, in the invention, a device is to be made available which has at least the following features.
The device is made as an electrooptical measurement device and is used to ascertain the relative position which is assumed by two bodies or surface areas of bodies with reference to one another. The device is made as a measurement arrangement with at least one light beam emitter and at least one optoelectronic position detector which acts along one axis or several axes, with a photosensitive measurement surface. The light beam emitter is suited for directing a focussed light beam of low divergence, for example a laser beam, onto the photosensitive measurement surface of the position detector. The position detector is able to deliver electrical signals which correspond to the coordinates of the instantaneous light beam impact point on the measurement surface. A combination of a diffuser (
40
) which is mounted in the housing and a projection objective lens (
50
), which combination widens the measurement area and which modifies the optical beam path, is optically connected upstream of the position detector.
The invention is improved by a process with which it is possible to determine the delivered coordinates of the instantaneous light beam impact point with especially high precision.
REFERENCES:
patent: 4518855 (1985-05-01), Malak
patent: 4906097 (1990-03-01), Wiedemann
patent: 5035503 (1991-07-01), Sadeh et al.
patent: 5077905 (1992-01-01), Murray, Jr.
patent: 5418562 (1995-05-01), Roundy et al.
patent: 5440338 (1995-08-01), Roundy et al.
patent: 6043889 (2000-03-01), Garner
patent: 6476914 (2002-11-01), Hoelzl et al.
patent: 675 910 (1990-11-01), None
patent: 197 47 872 (1999-05-01), None
patent: 199 53 451 (2000-06-01), None
patent: 0 316 624 (1989-05-01), None
patent: 0 807 801 (1994-11-01), None
patent: 0 962 746 (1999-12-01), None
patent: 2 268 021 (1993-12-01), None
patent: 2 330 470 (1998-10-01), None
patent: 2 330 470 (1999-04-01), None
patent: WO 98/33039 (1998-07-01), None
Tetlow S. et al., Three-Dimensional Measurmenet of Underwater Work Sites Using Structured Laser Light, Measurement Science and Technology, IOP Publishing, Bristol, GB, Bd. 10, Nr. 12, Dec. 1999, pp. 1162-1167.
Font Frank G.
Prüftechnik Dieter Busch AG
Punnoose Roy M.
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