Tool, device, and method for polishing lenses

Patent metadata

Field	Value
Publication number	US-2019126425-A1
Application number	US-201716307174-A
Country	US
Kind code	A1
Filing date	Jun 2, 2017
Priority date	Jun 6, 2016
Publication date	May 2, 2019
Grant date	—

Abstract

A tool, a device, and a method for zonal polishing of optical workpieces, wherein the tool has a preformed cap for forming a polishing surface, and the tool is placed against the workpiece that is to be polished in such a way that the tilt angle of the axis of rotation of the tool to the normal of the contact surface on the workpiece remains at least essentially constant and/or the size of the contact surface remains at least essentially constant.

First claim

1 - 30 . (canceled)

31 . A tool for polishing of optical workpieces, comprising:
a curved head having a curved end surface and an elastic cap arranged on the curved end surface of the curved head to form a polishing surface, the elastic cap being mounted so as to conform to the shape of the curved end surface of the head in a stress-free manner.

32 . The tool according to claim 31 , wherein the cap is formed of multiple layers.

33 . The tool according to claim 31 , wherein the cap has an intermediate element and a polishing element.

34 . The tool according to claim 33 , wherein at least one of the intermediate element or the polishing element is a preformed element that has been adapted to the shape of the curved end surface.

35 . The tool according to claim 33 , wherein the polishing element is a preformed element that is matched to the shape of the intermediate element.

36 . The tool according to claim 31 , wherein the cap has an at least essentially constant thickness.

37 . The tool according to claim 31 , further comprising a collar or other stop in proximity to the head for support of the cap on the peripheral side or for positioning of the cap.

38 . A device for polishing of optical workpieces, comprising:
a tool spindle for rotating a tool and a workpiece drive for rotating a workpiece that is to be polished, wherein the tool spindle and the workpiece drive are movable relative to one another, so that a polishing surface of the tool can be placed partially in an area of a contact surface against the workpiece that is to be polished, wherein the device has at least one of the following features: the tool being movable from an edge of a surface of the workpiece that is to be polished over the center of the workpiece to the opposite side of the edge, or at least one of a diameter of the contact surface or a tilt angle of between an axis of rotation of the tool and the normal of the contact surface being kept at least essentially constant during the polishing.

39 . The device according to claim 38 , wherein the tool is moved relative to the workpiece in such a way that the diameter of the contact surface is larger by a factor of at least 10 or 20, than a distance between adjacent tracks of a polishing path of the contact surface on a surface of the workpiece that is to be polished.

40 . The device according to claim 38 , wherein the workpiece drive forms a controlled axis of rotation for the workpiece.

41 . The device according to claim 38 , wherein the rotational speed of the workpiece is variable or controllable or feedback controllable during a rotation depending on at least one of rotating position, a profile of the workpiece, a diameter of the contact surface, an indentation depth of the polishing surface, contact pressure of the tool on the workpiece or locally desired dwell time or polishing time.

42 . The device according to claim 38 , wherein a plurality of different tools for use with different radii of curvature of the polishing surface are mountable to the tool spindle.

43 . The device according to claim 42 , wherein a distance of a swivel axis for swiveling the tool relative to the workpiece from a point of intersection of the axis of rotation of the tool spindle with the polishing surface is less than 100 mm.

44 . The device according to claim 42 , wherein a distance of a swivel axis for swiveling the tool relative to the workpiece from a point of intersection of the axis of rotation of the tool spindle with the polishing surface is at least essentially the same for all tools.

45 . A method for polishing of a surface of an optical workpiece, comprising:
swiveling or advancing a tool with a curved polishing surface relative to the workpiece, so that a polishing surface of the rotating tool is placed partially by indentation in the area of a contact surface against the rotating workpiece to be polished, the method further comprising at least one of the following steps: moving the tool from an edge of the surface of the workpiece that is to be polished over the center of the workpiece to the opposite side of the edge, keeping at least one of a diameter of the contact surface or a tilt angle between an axis of rotation of the tool and the normal of the contact surface at least essentially constant during the polishing of the workpiece, varying an indentation depth of the polishing surface by advancing the tool during the polishing of the workpiece, keeping a distance between adjacent tracks of a polishing path at least essentially constant, or varying rotational speed of the workpiece during a rotation.

46 . The method according to claim 45 , wherein the diameter of the contact surface is kept at least essentially constant by variation of the indentation depth.

47 . The method according to claim 45 , wherein the diameter of the contact surface decreases starting from an edge to the center of the surface that is to be polished and increases in the opposite direction.

48 . The method according to claim 45 , wherein the rotational speed of the workpiece increases starting from polishing on the edge to the center of the surface and decreases in the opposite direction.

49 . The method according to claim 45 , wherein the center of the contact surface traverses a spiral polishing path relative o the workpiece.

50 . The method according to claim 45 , wherein the contact surface is significantly smaller than the surface of the workpiece.

Assignees

• Schneider Gmbh & Co Kg

Inventors

• Schneider Gunter
• Huttenhuis Stephan
• Fedoseew Andreas
• Geist Nadine

Classifications

• B24B13/02

  by means of tools with abrading surfaces corresponding in shape with the lenses to be made · CPC title

• B24B13/01 Primary

  Specific tools, e.g. bowl-like; Production, dressing or fastening of these tools · CPC title

• B24B13/06

  grinding of lenses, the tool or work being controlled by information-carrying means, e.g. patterns, punched tapes, magnetic tapes · CPC title

• B24B9/14

  of optical work, e.g. lenses, prisms {(control of the position of the tool for bevelling optical work B24B47/225)} · CPC title

• B24B13/012

  conformable in shape to the optical surface, e.g. by fluid pressure acting on an elastic membrane · CPC title