Computer controlled work tool apparatus and method

• US 9,952,585 B2
• Filed: 08/26/2008
• Issued: 04/24/2018
• Est. Priority Date: 08/24/2007
• Status: Active Grant

• Current Assignee: Zeeko Limited
• Original Assignee: Zeeko Limited
• Inventors: Walker, David, Beaucamp, Anthony, Dunn, Christina
• Primary Examiner(s): HARTMAN JR, RONALD D
• Application Number:
  US12/674,952
• Publication Number:
  US 20110190922A1
• Time in Patent Office: 3,528 Days
• Field of Search: 700159, 700186, 700187, 700190
• CPC Class Codes: B24B 13/06 grinding of lenses, the tool or work being controlled by information-carrying means, e.g. patterns, punched tapes, magnetic tapes
• CPC Class Codes: B24D 13/142 Wheels of special form
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 19/4103 Digital interpolation
• CPC Class Codes: G05B 2219/34105 Area pocket machining, space filling curve, to cover whole surface
• CPC Class Codes: G05B 2219/34118 Using a pseudo-random or random tool path
• CPC Class Codes: G05B 2219/34141 B-spline, NURBS non uniform rational b-spline
• CPC Class Codes: G05B 2219/35122 Generate random paths along a raster path
• CPC Class Codes: G05B 2219/45157 Grind optical lens
• CPC Class Codes: G05B 2219/45199 Polish
• CPC Class Codes: G05B 2219/45232 CMP chemical mechanical polishing of wafer
• CPC Class Codes: G05B 2219/49352 7-Axis surface machining

Abstract

A polishing machine is described in which a surface treatment tool is moved across the surface of a workpiece in accordance with a predefined tool-path, in order to carry out the desired treatment process. The tool-path is non-periodic and preferably pseudo-random. Various techniques are described for generating data representing the tool-path to be followed. A technique is also described for determining optimum control parameters used to control the polishing machine for a given tool-path. The surface treatment may be a shaping technique in which material is removed from the surface, or a technique for adding material to the surface of the workpiece, or a technique for modifying the surface or a region under the surface of the workpiece.

Claims

1. An apparatus for performing a surface treatment on an area of a workpiece, the apparatus comprising:

a surface treatment tool having a treatment footprint and adapted to treat a material of the workpiece within the treatment footprint, the treatment comprising one or more of;

i. the removal of workpiece material from a surface of the workpiece;

ii. the addition of material to the surface of the workpiece; and

iii. the modification of the workpiece material at or under the surface of the workpiece;

a mechanism for moving the surface treatment tool along an irregular path relative to the workpiece such that the treatment footprint of the treatment tool passes over all points of the area of the workpiece;

and wherein the path visits all points of the area without visiting any point twice;

and wherein the path is arranged so that the transverse distance between neighbouring stretches of the path is substantially the same for all or substantially all points on the path.

2. An apparatus according to claim 1, wherein the transverse distance between neighbouring stretches of the path is arranged to be within a predetermined range of distances.

3. An apparatus for performing a surface treatment on an area of a workpiece, the apparatus comprising:

a surface treatment tool having a treatment footprint smaller than said area, and adapted to treat a material of the workpiece within the treatment footprint, the treatment comprising one or more of;

i. the removal of workpiece material from a surface of the workpiece;

ii. the addition of material to the surface of the workpiece; and

iii. the modification of the workpiece material at or under the surface of the workpiece;

a mechanism for moving the treatment footprint of the surface treatment tool along an irregular path relative to the workpiece such that the treatment footprint of the surface treatment tool passes over all points of the area of the workpiece;

and wherein the path is a random or pseudo-random path, and

wherein the path is arranged so that the transverse distance between neighbouring stretches of the path is different at different points along the path; and

wherein the path is arranged so that the transverse distance between neighbouring stretches of the path is reduced for points on the path which lie adjacent the edge of the area.