JPH03115909A - Dimension measuring instrument and measured value correcting method - Google Patents

Abstract

PURPOSE:To expand an application range while maintaining high dimension measurement accuracy by storing correction data in a nonvolatile memory provided in a detection part and reading it out to the volatile memory of a data processing part before measurement. CONSTITUTION:The detection part 19 has the nonvolatile memory 41 stored with the correction data for a calculated measured value and the data processing part has the volatile memory 36 for storing the correction data temporarily, a correction data transfer means 42 which reads the correction data out of the nonvolatile memory 41 and writes in the volatile memory 41 before an object body 28 begins to be measured, and a measured value correcting means 35 which corrects the calculated measured value of the measured body with the correction data stored in the volatile memory. Therefore, the detection part 19 can be connected to an optional data processing part.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a dimension measuring device that measures the dimensions of all fixed objects by irradiating light vibrated in a certain direction to the fixed objects, and a dimension measuring device thereof. The present invention relates to a measured value correction method for correcting measured values of an apparatus.

[Prior Art] A dimension measuring device that accurately measures the dimensions of an object in a non-contact manner using a laser beam is configured as shown in FIG. 4, for example. A laser beam 2 outputted from a light source 1 is reflected by a plane mirror 3 and then reflected by a plane mirror 5 attached to one free end of a tuning fork deflector 4. The tuning fork deflector 4 is driven by an electromagnetic coil 6 and vibrates at a constant frequency determined by its shape. Therefore, the laser beam 2 reflected by the plane mirror 5 also vibrates in a certain direction. The vibrating laser beam 2 is irradiated onto an object to be measured 9 via a half-mirror 7° collimator lens 8. The laser beam 2 that has passed through the object to be measured 9 is incident on the light receiver 11 via the condenser lens 10 .

On the other hand, the laser beam 2 reflected by the half mirror 7 is irradiated onto the base rod 13 for calibration via the collimator lens 12. The laser beam 2 that has passed through the reference rod 13 is passed through the condenser lens 14
The light enters the light receiver 15 via the light beam.

In such a dimension measuring device, the laser beam 2 has a period T determined by the vibration frequency of the tuning fork deflector 4 on the object to be measured 9 . is scanned in a direction perpendicular to the optical axis. Therefore, the signal waveform of the light reception signal a output from the light receiver 11 becomes a periodic waveform with a period T in which the signal is at a low (L) level for a period T during which light is blocked by the object to be measured 9.

Due to the presence of the reference rod 13, the light reception signal a2 outputted from the light receiver 15 is at L level only during the existence period of the reference rod 13, as shown in the figure. Then, from the edge count value of the received signal a2, the count value of the scan period and the value of the scan center position are determined. By subtracting the count value at the center position from each edge count value of the reference rod 13 and further dividing by the count value of the scanning period, the phase occupied by each edge in the scanning period is determined. Each phase can be converted into a value corresponding to each edge position using a function table showing the change in scanning position over time.

Although the difference between the edge positions obtained in this way changes depending on the scanning width, this value is set as the measured value MS of the reference bar.

The measurement value is determined from the received light signal a from the object to be measured 9 using the same procedure as that for the reference rod 13. is found. This measurement MD. The true measured value d of the ΔpI constant object 9 is calculated using the above-mentioned measured value Ms and the true value dR of the reference rod 13, although it also changes depending on the scanning width.

d=Do (dR/Ms) However, in the apparatus shown in FIG. 4, the laser beam 2 passes through the same path up to the half mirror 7.
Even if there is a change in the installation dimensions or characteristics of the optical member including the tuning fork deflector 4 until the beam is incident on the tuning fork deflector 7, this will affect the measurement of the dimensions of the object to be measured 9 and the reference device 13 under the same conditions. By performing dimensional measurements on the reference device 13 in advance, it is possible to correct the dimensional measurement results on the object to be measured 9.

However, the aberration of the collimator lens 8 and the half mirror 7
Although not shown in Fig. 4, it is used to seal the optical path folding mirror inserted after half mirror 7 and the optical system in order to downsize the optical system. Scanning distortion remains due to distortions and scratches in the optical window.

If such scanning distortion exists, there is a concern that the measured edge position of the object to be measured 9 may differ from the actual edge position. That is, each measured position in the direction orthogonal to the laser beam 2 and each actual position no longer completely match.

To solve this problem, a knife is inserted into the optical path, the knife position is gradually moved, and correction data showing the relationship between each measured value and each actual value at each moving position is calculated. Accordingly, the measured value of the actual measured object 9 is corrected.

Problems to be Solved by the Invention C] However, even in the dimension measuring device configured as described above, there are still problems as described below that need to be improved.

In other words, in general, a dimension measuring device has a detection section mainly composed of optical members as shown in FIG. It is composed of a data processing section that calculates the dimension d of the object 9 and displays or prints out the full constant value that is the calculation result.

Since the data processing unit executes a correction process of calculating correction data and correcting actual measured values using the correction data, the above-mentioned correction data is stored in the data processing unit.

However, if the correction data is stored in the data processing section, the detection section and the data processing section will always be used as a pair. In general, the size of the object to be measured and the measurement accuracy measured by a dimension measuring device are determined by the scanning width of the laser beam 2 in the detection section and the size of each lens 8° 10, and the specifications of the data processing section are exactly the same. Can be done. Therefore, it is desired that a plurality of detection units can be connected to one data processing unit.

However, since different correction data for each detection section is stored in the data processing section, it has been impossible to connect the data processing section to any detection section. Furthermore, when there are multiple data processing units, the detection unit cannot be connected to a data processing unit other than the one designated for itself.

In addition, if only the detection part breaks down, it is not possible to take only the detection part to the manufacturer's service station for repair.
It was necessary to bring along a normal data processing unit as well.

Furthermore, when manufacturing a dimension measuring device including such a detection section and a data processing section, the detection section and the data processing section are manufactured in separate processes, but it is always necessary to adjust them as a pair during the adjustment stage.

The present invention was made in view of these circumstances, and
By storing the correction data in the non-volatile memory provided in the detection unit, the detection unit can be connected to any data processing unit, even if the detection unit is affected by collimator lens aberration, half mirror distortion, distortion, etc. Even if a problem occurs, the same data processing unit can obtain correct dimension measurement values, expand the scope of application while maintaining high dimension measurement accuracy, and improve operability significantly. The object of the present invention is to provide a device and a method for correcting measured values.

[Means for Solving the Problems] In order to solve the above problems, the present invention irradiates an object to be measured with light that vibrates in the measurement direction, and uses a light receiver disposed behind the object to be measured. In a dimension measuring device consisting of a detection section that receives light and outputs a signal, and a data processing section that calculates the =j method of the measured object from the signal output from this detection section, the A non-volatile memory is provided to store correction data for the fixed value, and the data processing unit includes a volatile memory for temporarily storing the correction data, and a correction data stored in the non-volatile memory before the start of the measurement operation for the object to be measured. A correction data transfer means for reading data and writing it into a volatile memory, and a measurement value correction means for correcting a calculated measurement value of the object to be measured using the correction data stored in the volatile memory by the correction data transfer means. It has been established that

In addition, in the dimension measuring device according to another aspect of the present invention, there is provided a method for correcting measured values in the dimension measuring device, in which each moving position of the knife is measured by irradiating vibrating light onto a knife moving in a direction orthogonal to the vibration direction of the light. Then, the correction data determined by the relationship between each measured value and each actual position is calculated, and the calculated correction data is written to the nonvolatile memory provided in the detection unit, and then the correction data is written to the non-volatile memory provided in the detection unit, and then the correction data is The correction data stored in the nonvolatile memory is transferred to a volatile memory provided in the data processing section, and the measured value of the object to be measured is corrected using the correction data stored in the volatile memory. .

[Operation] According to the dimension measuring device configured as described above, correction data is stored in the nonvolatile memory provided in the detection section. This correction data is then transferred to the volatile memory provided in the data processing section before the actual measurement operation on the object to be measured. Then, the actually measured value of the object to be measured is corrected using the correction data stored in the volatile memory.

That is, since the correction data, which is data unique to the detection section, is stored within the detection section, this detection section can be connected to any data processing section.

According to another invention, a knife is inserted into the optical path of the light of the detection unit, and correction data indicating the relationship between each measured position of the knife and each actual position of the knife is created, and the created correction The data is once written to the nonvolatile memory of the detection unit. The correction data stored in the non-volatile memory is transferred to the volatile memory in the data processing section before starting the actual dimension measurement of the object to be measured. Therefore, the measured value is corrected using the correction data stored in this volatile memory.

The reason for using the correction data stored in the volatile memory in the data processing section when correcting the measured value is, for example, because the correction data in the non-volatile memory of the detection section connected via a serial transmission cable is read each time. The reason for this is that the continuous output time becomes longer and the responsiveness of measurement decreases.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a dimension measuring apparatus to which the measured value correction method of the embodiment is applied. This dimension measuring device is roughly divided into a detection section 19 consisting of an optical member and some electronic members.
and a data processing section 20 that calculates the dimensions of the object to be measured from the position of change in the signal level of the signal output from the detection section.

In the detection unit 19 , a laser beam 22 output from a laser light source 21 is reflected by a plane mirror 24 attached to one free end of a tuning fork deflector 23 .

Since the drive circuit 25 vibrates the tuning fork deflector 23 by passing an exciting current through the electromagnetic coil 26, the tuning fork deflector 23 vibrates at a constant frequency determined by its shape. Therefore, the laser beam 222 reflected by the plane mirror 24 also vibrates in the direction indicated by arrow A in the figure. The vibrating laser beam 22 passes through a half mirror 7 and is converted into parallel light by a collimator lens 27.
8 is irradiated. Laser light 2 that has passed through the object to be measured 28
2 is incident on the light receiver 30 via the condensing lens 29.

On the other hand, the laser beam 22 reflected by the half mirror 7 is irradiated onto a reference rod 13 for calibration via a collimator lens 12. The laser beam 22 that has passed through the reference device 13 is incident on the light receiver 15 via the condenser lens 14 . A calibration value (dR/
Ms) is calculated and sent to the dimension calculation circuit 34. Furthermore, the timing at which the laser beam 22 crosses the edge position of the reference rod 13 is detected, and the same <
The NJ method calculation circuit 35 is output.

Further, the received light signal output from the light receiver 30 is waveform-shaped by a waveform shaping circuit 31 to an H level or an L level, and then sent to the data processing section 20 via a signal line 33.

The waveform-shaped received light signal e inputted to the data processing section 20 is inputted to the edge detection circuit 32. Mechanism/Soji detection circuit 3
2 sequentially detects each signal level change that occurs when the laser beam 22 in the waveform-shaped received light signal e passes through the 6-edge position ■■ of the object to be measured 28, and determines the edge position ■■
An edge detection signal having a pulse corresponding to is sent to the next dimension calculation circuit 34.

The dimension calculation circuit 34 uses the calibration value (dR/Ms) obtained by measuring the reference rod 13 and the reference position signal, and
Calculate the distance D2 from the reference position indicated by the edge position of the reference rod 13 at the 6th machining and machining position ■■ from the input edge detection signal from each pulse position corresponding to the machining and machining position ■■. do.

Specifically, the dimension calculation circuit 34 is provided with a counter whose count value is reset each time the reference position signal is input. In addition, since the laser beam 22 vibrates in a sinusoidal manner, it is necessary to perform sinusoidal correction. For this purpose, a function table showing the relationship between each count value of the counter and the scanning light position is stored. ing. Then, each time the edge detection signal is input, the count value counted by the counter is latched by the latch circuit. The count value corresponding to each latched edge position (■) is converted into a scanning light position using the function table. Then, using the calibration value (dR/Ms), the distance from the reference position,
.

Calculate D2.

The distance D2 indicating the edge position output from the dimension calculation circuit 34 is input to the correction calculation circuit 35. The correction calculation circuit 35 stores correction data P + , corresponding to the distance D2, stored in a volatile memory 36 such as a RAM.
P2 is read out, and correction data P, are added to the manually input distances DI and D2, respectively.

P2 is added to calculate the correct distance MDO1+D02.

Next, the difference between the corrected distance I'llD (lI+D 02) is calculated and the dimension Do (=Do2 D
o+) is determined and displayed on the display 37a, and, if necessary, is printed out by the printer 37b.

5 Further, the distance before correction exposed by the dimension calculation circuit 34 is input to the correction data calculation section 38.

The correction data calculation unit 38 transfers the calculated correction data P to a non-volatile memory formed by an E2FROM (electrically writable and erasable continuous memory) provided in one detection unit via a switching circuit 39 and a transmission cable 40. sexual memory 4
Write to 1.

The measurement control unit 42 also reads out the correction data P stored in the nonvolatile memory 41 and stores it in the volatile memory 36, and also reads out the correction data P stored in the nonvolatile memory 41 and stores it in the volatile memory 36. The operation of the correction data calculation section 38 and the correction calculation circuit 35 is controlled.

FIG. 3 is a diagram for explaining data transmission between the nonvolatile memory 41 formed of E2PROM in the detection section 19 and the correction data calculation section 28 and measurement control section 42 in the data processing section 20. This nonvolatile memory 41 has a memory main body, a parallel/serial conversion circuit, a serial/parallel conversion circuit, etc. built therein. Additionally, a parallel/serial conversion circuit and a serial/parallel conversion circuit are incorporated in the correction data calculation unit 38 and measurement control unit 42 on the data processing unit 20 side, respectively.

Therefore, the nonvolatile memory 41 and the correction data calculation unit 2
Data transmission between the measurement controller 8 and the measurement control unit 42 is performed using a serial data transmission method. Therefore, the detection unit 1
The transmission cable 4o connecting the data processing section 9 and the data processing section 2o includes three signal lines 40a.

40b and 40c. In addition, each signal line 40
Receivers 43a, 43b and human driver 43c are inserted in portions a, 40b, 40c on the detection unit 19 side.

Next, the operation of the dimension measuring device configured as described above will be explained.

First, the procedure for calculating the correction data P will be explained.

First, the measurement control section 42 switches the switching circuit 39 to the correction data calculation section 38 side, and activates the correction data calculation section 38. Then, as shown in FIG. 2, the knife 44 is mounted on a movable table 45 and inserted at a constant speed at right angles to the optical path of the laser beam 22. The edge position M8 of the tip of the knife 44, which is indicated by the distance from the reference position described above, is precisely measured by the laser interferometer 46, and the correction piggy calculation unit 35
is input to.

On the other hand, the light reception signal regarding the edge position of the knife 44 output from the light receiver 30 is sent to the dimension calculation circuit 38 to determine the measured edge position M. is calculated.

Then, the correction data calculation unit 38 calculates correction data P(Mo) for the corresponding position.

P (Mo) = Mp M.

The calculated correction data P(Mo) is then stored in the internal memory.

While moving the knife 44 in accordance with the above-described procedure, correction data P for each measured edge position obtained by the dimension calculation circuit 34 is calculated. When the calculation process of all the correction data P is completed, the calculated correction data P is
After converting into serial data in a serial conversion circuit, the data is sent to the nonvolatile memory 41 of the detection unit 19 via the switching circuit 39 and the transmission cable 40. The non-volatile memory 41 returns the received serial correction data P to the original parallel correction data P and writes it into the memory main body. When the writing process of the correction data P to the nonvolatile memory 41 is completed, the measurement control section 42 switches the switching circuit 39 to the measurement control section 42 side, and stops the operation of the correction data detection section 38.

In such a state, the correction data P stored in the nonvolatile memory 41 will not disappear even if the detection section 19 is separated from the data processing section 20 or the power of the entire device is cut off.

Next, a procedure for actually measuring the dimensions of the object to be measured 28 will be explained.

First, when the power of the entire device is turned on with the detection section 19 and the data processing section 20 connected, the n1 constant control section 42 converts the correction data P stored in the nonvolatile memory 41 of the detection section 19 into serial data. The data is read out in this state, converted into parallel data, and written into the volatile memory 36. Thereafter, a measurement command is sent to the correction calculation circuit 35. Therefore, the correction calculation circuit 35 waits for input of the dimension value D9 from the dimension calculation circuit 34.

Then, as shown in FIG. 1, when the object to be measured 28 is inserted into the laser beam 22, the dimension calculation circuit 3
The dimension value is calculated in step 4. Then, this dimension value is determined to be the correct II fixed value using the correction data P read out from the volatile memory 36 by the correction calculation circuit 35. It is corrected to

With the dimension measuring device and measurement value correction method having such a configuration, differences in specifications in the detection unit 19, aberrations of the collimator lens 27, and distortion of a half mirror inserted in the middle or a mirror used to shorten the optical path can be avoided. Correction data P possessed by each detector 19 due to distortion or scratches is measured by the data processing section 20 and written into the nonvolatile memory 41 within the detection section 19 .

When the entire apparatus is powered on to start measuring the dimensions of the object to be measured 28, the correction data P stored in the nonvolatile memory 41 is written to the volatile memory 36 in the data processing section 20.

Note that the correction data P is moved from the non-volatile memory 41 to the volatile memory 036, and is executed within the warm-up time after turning on the power, so even if the correction data P is converted to serial data, Even if it is transmitted, there is no particular problem because the transmission process will be completed within the warm-up time.

When the API fixed object 28 is inserted into the laser beam 22 after the warm-up time has elapsed, the correction calculation circuit 35 outputs the correct dimension value after correction. is output and displayed on the display 37a. Note that since the correction data P is read out in parallel from the volatile memory 36 and corrected by the correction calculation circuit 35, the correction calculation speed is not reduced.

In this way, the correction data P specific to the detection section 19 is transmitted to the detection section 1.
Since the detection unit 19 is stored in the nonvolatile memory 41 in the data processing unit 9, even if the detection unit 19 is connected to a completely different data processing unit 20, the dimension measurement work for the object to be measured 28 can be immediately executed. Conversely, also on the data processing unit 20 side,
It becomes possible to connect to multiple types of detection units 19 with different specifications.

1. Therefore, only one data processing section 20 is prepared, and a plurality of detection sections 19 are used within the measurement range of the object to be measured.

Since it can be switched and used according to the measurement conditions such as measurement accuracy, the cost of the entire equipment can be significantly reduced compared to conventional equipment in which the detection part and data processing part must be used in pairs. can. Moreover, the installation area can also be reduced.

In addition, the above-mentioned correction data P is stored in the nonvolatile memory 41.
In addition, by setting data such as the measurement range and measurement accuracy of the detector 19, the data processing section 20 displays the corrected dimension value on the display 37a. It becomes possible to properly display the display range when displaying a value, the number of effective digits when displaying a measured value digitally, etc.

Note that the present invention is not limited to the embodiments described above. For example, the present invention can also be applied to a distance measuring device in which a detection section that measures distance by triangulation using laser light and a data processing section are separated.

[Effects of the Invention] As explained above, according to the dimension measuring device and the measured value correction method of the present invention, correction data is stored in a non-volatile memory provided in the detection unit, and data processing is performed before measurement. It is read out to the volatile memory of the unit. Therefore, the detection unit can be connected to any data processing unit,
Even if there is aberration of the collimator lens or a half mirror in the detection part,
Even if there is distortion or distortion, the same data processing unit can obtain correct dimensional measurements, expanding the scope of application while maintaining high dimensional measurement accuracy, and improving operability. It can be significantly improved.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the general configuration of a dimension measuring device according to an embodiment of the present invention, Fig. 2 is a schematic diagram showing a measured value correction method of the embodiment, and Fig. 3 is a main part of the device of the embodiment. FIG. 4 is a schematic diagram showing the general configuration of a conventional dimension measuring device. 19...Detection unit, 20...Data processing unit, 21...
- Laser light source, 22... Laser light, 23... Tuning fork deflector, 27... Collimator lens, 28... Measured object, 29... Condensing lens, 30... Light receiver, 31
... Waveform shaping circuit, 32 ... Edge detection circuit, 33 ... Dimension calculation circuit, 35 ... Correction calculation circuit, 36 ... Volatile memory, 38 ... Correction data calculation section, 39...Switching circuit, 41...Nonvolatile memory, 44...Nifetsuji.

Claims (2)

[Claims] (1) A measured object (28) is irradiated with light (22) vibrating in the measurement direction, and the light is received by a light receiver (30) disposed behind the measured object. A detection unit (19) that outputs a signal, and a data processing unit (20) that calculates the dimensions of the object to be measured from the signal output from this detection unit.
), the detection unit includes a nonvolatile memory (41) for storing correction data for the calculated measurement value, and the data processing unit includes a nonvolatile memory (41) for temporarily storing the correction data. volatile memory (36);
a correction data transfer means (42) for reading correction data stored in the non-volatile memory and writing it into the volatile memory before starting a measurement operation for the object to be measured; 1. A dimension measuring device comprising: a measured value correcting means (35) for correcting a calculated measured value of an object to be measured using correction data stored in the dimensional measuring device. (2) A detection unit that irradiates the object to be measured with light that oscillates at a constant period in the measurement direction, receives the light with a receiver placed behind the object to be measured, and outputs a signal. and a data processing unit that calculates the dimensions of the object to be measured from the signal output from the detection unit, the knife edge moving the vibrating light in a direction perpendicular to the vibration direction of the light. (44) to measure each movement position of the knife edge, calculate correction data determined by the relationship between each measurement value and each actual position, and transfer the calculated correction data to a nonvolatile device installed in the detection unit. The correction data stored in the non-volatile memory is transferred to the volatile memory provided in the data processing section, and the correction data stored in the volatile memory is written into the memory and before starting the measurement operation for the actual object to be measured. A method for correcting measured values in a dimension measuring apparatus, characterized in that the measured values of the object to be measured are corrected using data.