Coburn Optical Industries, Inc.

Raymond D Gregory

Merritt S Cook

Charles C Brissey

A recognition apparatus and method are provided for identifying the type of work piece loaded onto the rotating shaft chuck of an ophthalmic product generator. A digital electronic system supplies signals which control the angular displacement of the chuck. Each type of work piece has a unique pattern of passages aligned on a plane transverse to its rotational axis which rotate into and out of alignment with a single registration line in the plane. Unique signature data which identifies each type of work piece by the angular positions at which the passages come into and go out of alignment with the registration line is stored in the digital electronic system. A beam of light, preferably infrared, is continuously transmitted along the registration line during a signature rotation of the chuck. The angular positions of the loaded work piece and the status of an electrical signal generated when the light beam passes through the passages are detected and stored in the digital electronic system. The loaded work piece signature data is then sequentially compared with the unique signature data for each type of work piece that could be loaded into the generator. An electronic signal is transmitted by the digital electronic system upon determination of either a match or lack of a match. The transmitted signal may be used to continue or abort the generating process and/or to cause one or more unique messages descriptive of the job status to be visually displayed.

Method and apparatus for chucked work piece recognition

In a linear feedback servo control system, the motion profile for each axis is pre-filtered before it is introduced to the servo loop for that axis. The motion profile is pre-filtered by a filter having an inverse amplitude response to the amplitude response of the servo loop. Therefore, the composite amplitude response of the filter/servo loop combination is approximately ideal for all relevant frequencies. The pre-filtering is done using constant delay filters, whether high pass, low pass or hybrid, that exhibit a phase lag corresponding to a time delay that is essentially constant at all relevant frequencies. Each axis of synchronized motion is pre-filtered with constant delay filters having the same time delay constant, but selected so that the motion of each axis provides sufficient accuracy within the intended bandwidth of that particular axis. Consequently, while phase lag is not zero, there is essentially constant delay for all axes at all relevant frequencies. Therefore, synchronized motion is preserved because motion in all axes is delayed by a constant amount.

Constant delay filtering for synchronized motion on multiple axes

A method of speed optimization of a spindle component of a machine having multiple synchronized components moving along multiple axes over a motion profile. The method including a first step further including: obtaining a motion error value of a synchronous component over the motion profile as a function of frequency; identifying a plurality of contour portions of the motion profile; specifying the motion error tolerance for the motion profile according to the requirement of the application; calculating component numbers and component values of the synchronized component over a selected contour portion using a Fast Fourier Transform (FFT); selecting a first speed of the spindle component; calculating spindle frequency from the speed of the spindle component; and a second step further including: multiplying the spindle frequency by the component numbers to obtain tool component frequencies; calculating the motion error value for selected tool component frequencies; multiplying the motion error value of the frequency defined by the component number, and the component value to obtain an error prediction for each component number; combining the error predictions for each component number to obtain a maximum predicted motion error for the contour portion; comparing the maximum predicted motion error for the contour portion with the motion error tolerance wherein the maximum predicted motion error must be less than the motion tolerance; and selecting the greatest spindle speed wherein the maximum predicted motion error is less than the tolerance. The method of the present invention further includes interpolating the optimum spindle speed over the entire motion profile.

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Muskogee, OK, United States of America

Raymond D Gregory