US 6,813,536 B1Granted

Method and device for computer numerical control of machining of spectacle lenses

AssigneeWernicke & Co. GmbH

InventorLutz Gottschald

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Abstract

The present invention relates to a method and a device for machining glass-lenses using a glass-lens machining apparatus with computerized numerical control. The method of the present invention comprises the following steps: introducing opto-metrical data relating to the glasses support into the computer of the apparatus control device which is provided with a host connection; introducing into the computer the data corresponding to the shape of a selected rim for glasses; introducing into the computer data about the material of the non-machined lens; calculating the required diameter of the glass-lens and displaying the result; introducing a non-machined lens into the apparatus; optionally calculating, e.g. in the host computer, the gradient of a bevel, groove or bezel on the shaped glass-lens according to the data introduced or to the front or back curves which are inherent to the existence of surfaces; and carrying out the computerized numerical-control machining of the non-machined lens.

Claims30

Dependent claims

A method of computer numerically controlled (CNC) spectacle lens machining comprising the steps of:

inputting optometric data of a spectacle wearer, including diopter number, values and angles of a cylindrical or prismatic cut, and power and position of a near portion, to a computer associated with a control unit of a lens machining apparatus;
inputting an interpupillary distance (PD) value to the computer corresponding to a selected spectacle frame;
inputting data to the computer representing the shape of the selected spectacle frame, and the curvature, shape, and periphery of a bezel of the selected spectacle frame
inputting data to the computer identifying the material of a selected spectacle lens;
computing a required lens blank diameter from the inputted data;
visually displaying the lens blank diameter;
inserting a lens blank of the required diameter into the lens machining apparatus;
computing the curvature of a bevel on the spectacle lens to be machined from one or more of the optometric data, PD values, shape data, radii of the front or back surface, and center thickness of the spectacle lens;
generating CNC machining data based on the computed curvature;
comparing data characterizing the bezel of the selected spectacle frame with data characterizing a portion of a spectacle edge cutting tool in the machining apparatus and determining from the comparison if machining of a required bevel is possible, and if so, if any correction to the CNC machining data is required;
if correction of the CNC machining data is required to permit machining of the bevel, determining required correction values for the machining data as a function of predetermined machining, workpiece and tool tolerances, and established deviations, and incorporating the correction values in the machining data;
CNC machining of the lens blank according to the machining data with any incorporated correction values to form the peripheral shape and bevel of the lens.

9 more elements

A spectacle lens machining apparatus comprising:

a housing;
a machining chamber in the housing including therein a spectacle lens holding shaft and an installed edge machining tool;
a computer-operated control device for controlling the machining by the edge machining tool of a lens blank held by the spectacle lens holding shaft;
an input keyboard connected to the computer,
a data reading device connected to the computer for reading spectacle lens machining data stored on a data storage medium, and/or a scanning unit connected to the computer for scanning the spectacle lens opening in a selected spectacle frame and the curvature, cross-sectional shape, and periphery of a bezel in the spectacle frame, and
a recognition device connected to the computer and operative to recognize the shape and dimensions of a bezel in the installed spectacle lens edge machining tool,
the computer being operative to:
generate CNC machining data;
compare data characterizing the shape of the bezel in the selected spectacle frame with data characterizing a portion of the shape of the edge machining tool;
determine from the comparison if machining of a required bevel is possible with the edge machining tool, and if so, if any correction to the CNC machining data is required;
if correction of the CNC machining data is required to permit machining of the bevel, determine required correction values for the machining data as a function of predetermined machining, workpiece and tool tolerances, and established deviations, and incorporate the correction values in the machining data;
and
operate the control device to machine the lens blank according to the machining data including any required correction values to form the peripheral shape and bevel for the lens.

10 more elements

Dependencies are inferred from the claim text.