§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
EP0643286A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Measuring device for determining the displacement of a movable object

Assignee: Koninklijke Philips NV
•
Filing: 1994-09-07
•
Granted: —
•
Expires: 2014-09-07
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A measuring device is described for determining the displacement of a movable object in cooperation with a graduation element (13) which is mechanically connected to the object whose displacement is to be determined. The graduation element (13) comprises at least a track (15) which is formed from a plurality of successive grating strips (16) located transversely to the direction of movement of the object. The measuring device (1) comprises a radiation source (3), a detector (7) and a reflective optical system which comprises at least a collimating element (5). The reflective optical system guides the radiation from the radiation source (3) to the graduation element (13) and changes it to an elongate radiation beam which is parallel on average in the cross-section perpendicular to the grating strips (16).

Inventors

  • 👤 Johannes Wilhelmus Dorotheus Bosch
  • 👤 Josephus Johannes Maria Braat
  • 👤 Joannes Gregorius Bremer

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-29 17:40
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/347; G01D5/34707; G01D5/34715

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 121 words
A measuring device for determining the displacement of a movable object in cooperation with a graduation element connected to the object and having at least a track which is formed from a plurality of successive grating strips extending transversely to the direction of movement of the object, said measuring device comprising at least a radiation source for generating radiation and an associated optical system for converting the radiation into a radiation beam which is parallel on average and for guiding said radiation beam towards the graduation element, and a radiation-sensitive detection system for converting radiation from the graduation element into an electric signal, characterized in that the optical system is a reflective optical system and comprises at least a collimating element.
Claim 2
Dependent Claim 33 words
A measuring device as claimed in Claim 1, characterized in that the collimating element is an off-axis portion of a rotationally symmetrical rotational paraboloid, with the radiation source being arranged in its focus.
Claim 3
Dependent Claim 89 words
A measuring device as claimed in Claim 1, characterized in that the collimating element is a parabolically cylindrical mirror whose cylindrical axis is parallel to a plane constituted by a grating strip and the normal on the graduation element and whose cross-section perpendicular to said plane is parabolic, and in that the optical system further comprises, between said mirror and the radiation source, an elliptically cylindrical mirror whose cylindrical axis is perpendicular to the grating strips and whose cross-section in a plane parallel to the grating strips is elliptic.
Claim 4
Dependent Claim 27 words
A measuring device as claimed in any one of Claims 1 to 3, characterized in that the optical system further comprises at least a flat folding mirror.
Claim 5
Dependent Claim 43 words
A measuring device as claimed in any one of the preceding Claims, characterized in that the radiation source and the detection system are present in a housing and the elements of the reflective optical system are incorporated in the walls of the housing.
Claim 6
Dependent Claim 31 words
A measuring device as claimed in any one of the preceding Claims, characterized in that at least the collimating element of the elements of the optical system has an aspherical surface.

References Cited (Backward Citations)

DE2002891A1 Cited
US4340814A Cited
JPS6031016A Cited
DE9006491U1 Cited

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag