JP2006224192A - Correction working method and correction working device used for it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a correction working method by which it is possible to prevent occurrence of uncorrected parts due to a difference in frequency characteristics and that of in working characteristics for each position of a working system. <P>SOLUTION: Filtering, in which the frequency characteristics of the working system obtained with another means by executing frequency analysis is taken into consideration, is executed to a distribution for each position of an error obtained by measuring working results. Alternatively, a window function, in which the working characteristics at each position of the working system obtained with another means is taken into consideration, is multiplied to the distribution for each position of the error. Eventually, it is possible to prevent the occurrence of the uncorrected parts due to the difference in frequency characteristics and that of in the working characteristics for each position of the working system. Consequently, it is also possible to correct errors that are not removed by conventional correction working and caused by the difference in frequency characteristics and that of in the working characteristics for each position of the working system. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

When processing accuracy is strictly required, such as an optical lens or a semiconductor component, correction processing is generally performed for processing once performed according to an error factor.
The present invention relates to the above-described correction processing technique, and further, a correction processing method in which a correction residue is not generated due to a difference in frequency characteristics of the processing system and processing characteristics at each position, and correction used in the method. The present invention relates to a processing apparatus.

In recent years, with the development of information communication technology, higher definition imaging functions and higher density information recording have been required. As a result, the demand for the dimensional accuracy of optical members used in the input / output unit of equipment has become stricter.
For example, Patent Document 1 discloses an automatic curvature correction processing method and apparatus for improving the curvature accuracy of a lens.

JP 2000-326192 A

  In addition, in order to improve accuracy, as another method different from the above conventional example, the tool position and the origin are precisely adjusted, and the tool positioning coordinates and the tool positioning coordinates are calculated and controlled, The processing machine is adjusted to the best condition and processed, and the remaining shape error (elastic deformation and thermal deformation of the tool and workpiece) is measured, and the same deformation is simply measured in the opposite direction. A method is also known in which the error is reduced by superimposing it on the tool trajectory information so as to cancel the previous error amount.

However, in the case of the latter correction processing method, there are many cases in which correction cannot be performed only by conventional simple error superposition.
The reason is that the correction efficiency varies depending on the shape of the error depending on the time and spatial frequency characteristics of all the processing systems including the processing machine, and thus the error cannot be removed by uniform correction. Furthermore, when the machining characteristics including the machining machine are spatially different from place to place, errors cannot be removed even if uniform correction is performed.

  Therefore, the present invention is a filter process (low-pass filter process, taking into account the frequency characteristics of the processing apparatus obtained by another means by performing frequency analysis on the error-by-position distribution obtained by measuring the processing result. High pass filter processing, etc.) or by multiplying the window function that takes into account the machining characteristics at each position of the machining apparatus obtained by another means. Make sure that no residual correction occurs due to differences in processing characteristics. For this reason, it is possible to correct errors caused by differences in the frequency characteristics of the machining apparatus and the machining characteristics at each position, which could not be removed by conventional correction machining.

For this reason, the technical solution means adopted by the present invention is:
In the correction processing method that measures the shape of the workpiece after processing and performs correction processing according to the error, using both the frequency characteristics of the processing machine and the error data, the frequency of the processing machine for each frequency component of the error data This is a correction processing method in which correction data is created so as to cancel the variation in processing efficiency for each time, and correction processing is performed.
Also, in the correction processing method that measures the shape of the workpiece after processing and performs correction processing according to the error, the error distribution of error data using both processing efficiency and error data at each processing point of the processing machine On the other hand, the correction processing method is such that correction data is generated and correction processing is performed so as to cancel the variation in processing efficiency for each place (for example, for each radius value in the case of axis target processing) of the processing machine.
Further, the correction processing apparatus used in the correction processing method described above, the processing apparatus measures the processing machine and how accurately the shape of the workpiece is made after the workpiece is processed. And a data processing device that calculates a correction amount based on data from the measurement device and feeds back the data to the processing machine.

  According to the present invention described above, even if the processing efficiency differs for each frequency characteristic or spatial location of the processing machine, correction processing can be performed efficiently, and specifications can be satisfied with a small number of correction processing. Become.

  The present invention uses both the frequency characteristics of the processing machine and the error data to create correction data so as to cancel the variation in processing efficiency for each frequency of the processing machine with respect to each frequency component of the error data. I did it. Also, using both the processing efficiency and error data at each processing point of the processing machine, for each location of the processing machine (for example, for each radius value in the case of axis target processing), the error data is distributed to the question distribution. Correction data was created so as to cancel the variation in machining efficiency), and correction machining was performed.

  Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a machining system according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a processing machine for processing a workpiece (hereinafter referred to as a workpiece). For example, ULG100 manufactured by Toshiba Machine Co., Ltd. or an equivalent machine can be used. Reference numeral 2 denotes a work. 3 is a measuring device for measuring how accurately the shape of the workpiece is made with respect to the design value after machining the workpiece. As this measuring device, Talysurf manufactured by Taylor Hobson or equivalent measurement is used. Can be used. Reference numeral 4 denotes a data processing device that can be realized using a general-purpose personal computer.
The above is a block diagram of a correction processing apparatus as an embodiment of the present invention.

Hereinafter, the operation of the correction processing apparatus will be described with reference to the flowchart of FIG.
After the start of processing (step 201), in step 202, the workpiece 2 is attached to the processing machine 1, and the workpiece 2 is processed using the processing machine 1 according to the design value. After the processing is completed, the workpiece 2 is removed from the processing machine 1 in step 203 and attached to the measuring device 3 to measure the shape. After the shape measurement, in step 204, the data processing device 4 is used to perform various processing on the measurement data to determine whether the shape accuracy is sufficient for the required specifications and to calculate data used in the correction process. If the shape accuracy is sufficient for the required specifications, the process goes to step 206 to finish the processing.
If it is determined in step 204 that the shape accuracy is not sufficient, the process goes to step 205 to reattach the work 2 to the processing machine 1 and correct the work 2 by the processing machine 1 based on the calculated correction data. Processing. If correction | amendment processing is completed, it will return to step 203 and will restart from shape measurement. Since many measuring devices 3 have a function of calculating an error with respect to a measurement value when shape information is input, the measuring device may be provided with an error calculating function (part).

  In this way, the error is reduced by repeating the correction process, and finally a product that satisfies the specifications is produced. However, if a simple machining error is used in the correction machining data calculation in step 204 as in the prior art, the correction machining data is used due to the difference in the frequency characteristics of the correction machining apparatus and the machining characteristics at each position. Since the efficiency is different, correct correction processing may not be performed, and correction processing may be repeated many times due to inefficiency, or the specification may still not be satisfied.

Next, the correction processing method according to the present invention will be described with reference to FIG.
By another means, in the correction processing apparatus of FIG. 1, it is known that the processing efficiency of the processing machine 1 in the high frequency region of the air frequency is not as good as that of the low frequency region. In such a correction processing apparatus, it is assumed that error data as shown in FIG. 3A is obtained in step 204 of FIG. In this case, if the error shape is simply input as the correction processing data, the processing efficiency in the high frequency region of the processing machine 1 is poor, so that the high frequency component is not sufficiently corrected. Therefore, in this correction processing method, the error information in FIG. 3A is divided into the high frequency component in FIG. 3B and the low frequency component in FIG. 3C in the data processing apparatus, as shown in FIG. The correction process is performed by changing the data to emphasize the high frequency component. By doing so, it is possible to efficiently correct errors of high frequency components that cannot be corrected by simply superimposing errors.
In the above example, for the sake of simplicity, it is assumed that the high frequency characteristics of the processing machine 1 are simply poor and one high frequency and low frequency are simply superimposed on the error. It goes without saying that the same idea holds even if the characteristics are more complex and the error waveform is more complex. In this case, the extraction and emphasis / suppression of the frequency component can be directly applied to the digital filter technology used in the audio and video fields, and therefore the details of the description are omitted.

Next, another correction processing method according to the present invention will be described with reference to FIG.
By another means, in the correction processing apparatus of FIG. 1, it is known that the processing efficiency of the processing machine 1 is not as good as the processing efficiency in the peripheral portion compared to that in the central portion. In such a processing apparatus, it is assumed that error data as shown in FIG. 4A is obtained in step 204 of FIG.
In this case, if the error shape is simply input as correction processing data, the processing efficiency in the peripheral portion of the processing machine 1 is poor, and thus the peripheral portion is not sufficiently corrected. Therefore, in this processing method, in the data processing apparatus, the error information in FIG. 4A is weighted so that the value in the peripheral part is larger than the value in the central part as shown in FIG. In the image processing and the data processing, it is multiplied by a window function), and the correction processing is performed by changing the peripheral portion to the emphasized data as shown in FIG. By doing this, it becomes possible to efficiently correct the peripheral error that cannot be corrected by simply superimposing the error.
In the above example, it is assumed that the peripheral characteristics of the processing machine 1 are simply poor in order to simplify the description. However, for each processing place of the processing machine 1 (for example, in the case of axial target processing, It goes without saying that even if the efficiency characteristic of (radius value) is more complicated, the same idea holds if the window function is changed accordingly.

Next, a specific implementation example of performing filter processing using a low-pass filter will be described with reference to FIG. FIG. 5A shows a sine wave with a cycle of L / 4, and FIG. 5B shows a sine wave with a cycle of L. When expressed by a mathematical formula, FIG. 5A shows y = A × (1−cos (8πx / L) (1)
In FIG. 5 (b), y = A × (1-cos (2πx / L)) (2)
It is represented by
When actually performing numerical control processing, the x direction is divided into, for example, 360, and FIG. 5A shows Xi = L × i / 360.
yi = A × (1−cos (8πi / 360)) i = 0, 1, 2... 360 (3), and FIG. 5B shows Xi = L × i / 360.
yi = A × (1-cos (2πi / 360)) i = 0, 1, 2,... 360 (4)
As a low-pass filter that can be realized very easily, there is a method called moving average.
This is an average of n points before and after yi as a sequence of points, that is,

の演算により得られるものである。

It is obtained by the calculation.

Specifically, for the two cases (a) and (b) in FIG. 5, in reference numerals 2, 3, and 4, 2: Average of 7 points before and after 3: Average of 20 points before and after 4: Average of 45 points before and after Is taken. (In order to simplify the calculation, it was calculated that the shape of the interrogation period was continuous before and after 0 to L.)
As can be seen from the figure, when taking a moving average of 45 points at the front and rear (L / 4 in width), the shape almost disappears in FIG. 5A, but the shape hardly changes in FIG. 5B.
Therefore, when the shape of the spatial frequency L / 4 and the spatial frequency L is mixed in the work, the L / 4 component can be removed by taking a moving average of front and rear L / 8 (width L / 4). Further, by subtracting the original shape from which the L / 4 modulus is removed, the L / 4 component can be obtained.

  In the above description, in order to simplify the description, only the spatial frequencies with periods of L and L / 4 have been extracted and described, but the same can be considered even if other components are included. Although the moving average is taken as an example of the low-pass filter, it is needless to say that a low-pass filter having a more complicated and steep characteristic, a high-pass filter, a band-pass filter, and the like can be similarly considered.

Next, the air frequency characteristics of the machine to be processed will be described. As shown in FIG. 6, for example, a shape A having a period L and a shape B having a period L / 4 are actually processed as indicated by broken lines, as shown in FIG. Suppose that If a is almost 100% of the design value and b is only 50% of the design value, the correction of the period L may be performed as it is, but the correction of the period L / 4 is doubled. Must be executed.
Here, in order to simplify the explanation, an example of only two types of spatial frequencies is given, but the same can be considered even if other spatial frequencies are mixed.

  Next, the processing characteristic distribution for each location of the processing machine will be described with reference to FIG. Suppose that the result of actually processing a shape A having a period of L / 10 as shown in FIG. 7, for example, as shown in FIG. If the center part is processed almost 100% of the design value and the outermost part is processed only 33% of the design value, the center part may be corrected as it is, but the outermost part of the correction is emphasized three times. In addition, the intermediate part must be carried out by converting the efficiency of each place.

  Next, the concept of correction in consideration of the machining shape and the characteristics of the machine will be described with reference to FIG. If the actual shape of the workpiece is in the shape of a solid line A in FIG. 8, a machining command that gives a broken line shape C is issued to the workpiece, and the resulting shape is a one-dot chain line B. Suppose that When the processing instruction at the point X is gl (x) but the actual processing amount is g2 (x), the correction processing amount is weighted with gl (x) / g2 (x). The correct amount is processed. The processing from A to C may be the previous correction processing or the test shape.

  The correction processing method and apparatus according to the present invention have been described above, but the present invention can be implemented in various other forms without departing from the spirit and main features thereof. For this reason, the above-described embodiments are merely examples, and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used in a method for processing an optical member used in an input / output unit of an optical apparatus that has been required to have a high-definition imaging function and higher-density information recording.

It is a block diagram of the processing apparatus concerning one example of the present invention. It is a flowchart for demonstrating operation | movement of the processing apparatus of FIG. It is operation | movement explanatory drawing of the characteristic improvement when the processing efficiency with respect to the high frequency region of a processing machine is inferior using the processing apparatus of FIG. It is operation | movement explanatory drawing of the characteristic improvement in case the processing efficiency in the peripheral part of a processing machine is inferior to that of a center part using the processing apparatus of FIG. FIGS. 5A and 5B are diagrams for explaining a specific implementation example in which filter processing is performed using a low-pass filter. FIG. 5A illustrates a sine wave having a cycle of L / 4, and FIG. It is a figure which shows the result of having actually processed the shape A with a period L, and the shape B with a period of L / 4. It is explanatory drawing about the process characteristic distribution for every place of a processing machine. It is a figure explaining the idea of amendment in consideration of processing shape and the characteristic of a processing machine.

Explanation of symbols

1 Processing Machine 2 Workpiece 3 Measuring Device 4 Data Processing Device

Claims (3)

In a machining method that measures the shape of the workpiece after machining and performs correction machining according to the error, using both the frequency characteristics of the machine and the error data, each frequency component of the machine is used for each frequency component of the error data. Correction processing method in which correction data is created and correction processing is performed so as to cancel the variation in processing efficiency. In the machining method that measures the shape of the workpiece after machining and performs correction machining according to the error, using both the machining efficiency and error data at each machining point of the machine, the error data distribution A correction processing method in which correction data is generated and correction processing is performed so as to cancel out variations in processing efficiency for each location of the processing machine (for example, for each radius value in the case of axis target processing). 3. A correction machining apparatus used in the correction machining method according to claim 1 or 2, wherein the machining apparatus and the machining machine and how accurately the shape of the workpiece after machining the workpiece is compared with the design value. A correction processing device comprising: a measuring device for measuring whether or not the device is made; and a data processing device for calculating a correction amount based on data from the measuring device and feeding back the data to the processing machine.

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